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Constructors of class basic_json, copy/move constructor, copy assignment, static functions creating objects, and the destructor.
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static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | array (initializer_list_t init={}) |
| | explicitly create an array from an initializer list More...
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static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | object (initializer_list_t init={}) |
| | explicitly create an object from an initializer list More...
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| | basic_json (const detail::json_ref< basic_json > &ref) |
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| | basic_json (const value_t v) |
| | create an empty value with a given type More...
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| | basic_json (std::nullptr_t=nullptr) noexcept |
| | create a null object More...
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| template<typename CompatibleType , typename U = detail::uncvref_t<CompatibleType>, detail::enable_if_t< not detail::is_basic_json< U >::value and detail::is_compatible_type< basic_json_t, U >::value, int > = 0> |
| | basic_json (CompatibleType &&val) noexcept(noexcept(JSONSerializer< U >::to_json(std::declval< basic_json_t & >(), std::forward< CompatibleType >(val)))) |
| | create a JSON value More...
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| template<typename BasicJsonType , detail::enable_if_t< detail::is_basic_json< BasicJsonType >::value and not std::is_same< basic_json, BasicJsonType >::value, int > = 0> |
| | basic_json (const BasicJsonType &val) |
| | create a JSON value from an existing one More...
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| | basic_json (initializer_list_t init, bool type_deduction=true, value_t manual_type=value_t::array) |
| | create a container (array or object) from an initializer list More...
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| | basic_json (size_type cnt, const basic_json &val) |
| | construct an array with count copies of given value More...
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| template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value orstd::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0> |
| | basic_json (InputIT first, InputIT last) |
| | construct a JSON container given an iterator range More...
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| | basic_json (const basic_json &other) |
| | copy constructor More...
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| | basic_json (basic_json &&other) noexcept |
| | move constructor More...
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| basic_json & | operator= (basic_json other) noexcept(std::is_nothrow_move_constructible< value_t >::value andstd::is_nothrow_move_assignable< value_t >::value andstd::is_nothrow_move_constructible< json_value >::value andstd::is_nothrow_move_assignable< json_value >::value) |
| | copy assignment More...
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| | ~basic_json () noexcept |
| | destructor More...
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Direct access to the stored value of a JSON value.
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| template<typename BasicJsonType , detail::enable_if_t< std::is_same< typename std::remove_const< BasicJsonType >::type, basic_json_t >::value, int > = 0> |
| basic_json | get () const |
| | get special-case overload More...
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| template<typename BasicJsonType , detail::enable_if_t< not std::is_same< BasicJsonType, basic_json >::value anddetail::is_basic_json< BasicJsonType >::value, int > = 0> |
| BasicJsonType | get () const |
| | get special-case overload More...
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| template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< not detail::is_basic_json< ValueType >::value anddetail::has_from_json< basic_json_t, ValueType >::value andnot detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0> |
| ValueType | get () const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >(), std::declval< ValueType & >()))) |
| | get a value (explicit) More...
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| template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< not std::is_same< basic_json_t, ValueType >::value anddetail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0> |
| ValueType | get () const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >()))) |
| | get a value (explicit); special case More...
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| template<typename ValueType , detail::enable_if_t< not detail::is_basic_json< ValueType >::value anddetail::has_from_json< basic_json_t, ValueType >::value, int > = 0> |
| ValueType & | get_to (ValueType &v) const noexcept(noexcept(JSONSerializer< ValueType >::from_json(std::declval< const basic_json_t & >(), v))) |
| | get a value (explicit) More...
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| template<typename T , std::size_t N, typename Array = T (&)[N], detail::enable_if_t< detail::has_from_json< basic_json_t, Array >::value, int > = 0> |
| Array | get_to (T(&v)[N]) const noexcept(noexcept(JSONSerializer< Array >::from_json(std::declval< const basic_json_t & >(), v))) |
| |
| template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0> |
| auto | get_ptr () noexcept-> decltype(std::declval< basic_json_t & >().get_impl_ptr(std::declval< PointerType >())) |
| | get a pointer value (implicit) More...
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| template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value andstd::is_const< typename std::remove_pointer< PointerType >::type >::value, int >::type = 0> |
| constexpr auto | get_ptr () const noexcept-> decltype(std::declval< const basic_json_t & >().get_impl_ptr(std::declval< PointerType >())) |
| | get a pointer value (implicit) More...
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| template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0> |
| auto | get () noexcept-> decltype(std::declval< basic_json_t & >().template get_ptr< PointerType >()) |
| | get a pointer value (explicit) More...
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| template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0> |
| constexpr auto | get () const noexcept-> decltype(std::declval< const basic_json_t & >().template get_ptr< PointerType >()) |
| | get a pointer value (explicit) More...
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| template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value, int >::type = 0> |
| ReferenceType | get_ref () |
| | get a reference value (implicit) More...
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| template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value andstd::is_const< typename std::remove_reference< ReferenceType >::type >::value, int >::type = 0> |
| ReferenceType | get_ref () const |
| | get a reference value (implicit) More...
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| template<typename ValueType , typename std::enable_if< not std::is_pointer< ValueType >::value andnot std::is_same< ValueType, detail::json_ref< basic_json >>::value andnot std::is_same< ValueType, typename string_t::value_type >::value andnot detail::is_basic_json< ValueType >::valueand not std::is_same< ValueType, std::initializer_list< typename string_t::value_type >>::valueand not std::is_same< ValueType, typename std::string_view >::valueand detail::is_detected< detail::get_template_function, const basic_json_t &, ValueType >::value, int >::type = 0> |
| | operator ValueType () const |
| | get a value (implicit) More...
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Access to the JSON value.
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| reference | at (size_type idx) |
| | access specified array element with bounds checking More...
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| const_reference | at (size_type idx) const |
| | access specified array element with bounds checking More...
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| reference | at (const typename object_t::key_type &key) |
| | access specified object element with bounds checking More...
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| const_reference | at (const typename object_t::key_type &key) const |
| | access specified object element with bounds checking More...
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| reference | operator[] (size_type idx) |
| | access specified array element More...
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| const_reference | operator[] (size_type idx) const |
| | access specified array element More...
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| reference | operator[] (const typename object_t::key_type &key) |
| | access specified object element More...
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| const_reference | operator[] (const typename object_t::key_type &key) const |
| | read-only access specified object element More...
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| template<typename T > |
| reference | operator[] (T *key) |
| | access specified object element More...
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| template<typename T > |
| const_reference | operator[] (T *key) const |
| | read-only access specified object element More...
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| template<class ValueType , typename std::enable_if< std::is_convertible< basic_json_t, ValueType >::value, int >::type = 0> |
| ValueType | value (const typename object_t::key_type &key, const ValueType &default_value) const |
| | access specified object element with default value More...
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| string_t | value (const typename object_t::key_type &key, const char *default_value) const |
| | overload for a default value of type const char* More...
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| template<class ValueType , typename std::enable_if< std::is_convertible< basic_json_t, ValueType >::value, int >::type = 0> |
| ValueType | value (const json_pointer &ptr, const ValueType &default_value) const |
| | access specified object element via JSON Pointer with default value More...
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| string_t | value (const json_pointer &ptr, const char *default_value) const |
| | overload for a default value of type const char* More...
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| reference | front () |
| | access the first element More...
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| const_reference | front () const |
| | access the first element More...
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| reference | back () |
| | access the last element More...
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| const_reference | back () const |
| | access the last element More...
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| template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value orstd::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0> |
| IteratorType | erase (IteratorType pos) |
| | remove element given an iterator More...
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| template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value orstd::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0> |
| IteratorType | erase (IteratorType first, IteratorType last) |
| | remove elements given an iterator range More...
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| size_type | erase (const typename object_t::key_type &key) |
| | remove element from a JSON object given a key More...
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| void | erase (const size_type idx) |
| | remove element from a JSON array given an index More...
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| void | clear () noexcept |
| | clears the contents More...
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| void | push_back (basic_json &&val) |
| | add an object to an array More...
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| reference | operator+= (basic_json &&val) |
| | add an object to an array More...
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| void | push_back (const basic_json &val) |
| | add an object to an array More...
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| reference | operator+= (const basic_json &val) |
| | add an object to an array More...
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| void | push_back (const typename object_t::value_type &val) |
| | add an object to an object More...
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| reference | operator+= (const typename object_t::value_type &val) |
| | add an object to an object More...
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| void | push_back (initializer_list_t init) |
| | add an object to an object More...
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| reference | operator+= (initializer_list_t init) |
| | add an object to an object More...
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| template<class... Args> |
| reference | emplace_back (Args &&...args) |
| | add an object to an array More...
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| template<class... Args> |
| std::pair< iterator, bool > | emplace (Args &&...args) |
| | add an object to an object if key does not exist More...
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| template<typename... Args> |
| iterator | insert_iterator (const_iterator pos, Args &&...args) |
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| iterator | insert (const_iterator pos, const basic_json &val) |
| | inserts element More...
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| iterator | insert (const_iterator pos, basic_json &&val) |
| | inserts element More...
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| iterator | insert (const_iterator pos, size_type cnt, const basic_json &val) |
| | inserts elements More...
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| iterator | insert (const_iterator pos, const_iterator first, const_iterator last) |
| | inserts elements More...
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| iterator | insert (const_iterator pos, initializer_list_t ilist) |
| | inserts elements More...
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| void | insert (const_iterator first, const_iterator last) |
| | inserts elements More...
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| void | update (const_reference j) |
| | updates a JSON object from another object, overwriting existing keys More...
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| void | update (const_iterator first, const_iterator last) |
| | updates a JSON object from another object, overwriting existing keys More...
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| void | swap (reference other) noexcept(std::is_nothrow_move_constructible< value_t >::value andstd::is_nothrow_move_assignable< value_t >::value andstd::is_nothrow_move_constructible< json_value >::value andstd::is_nothrow_move_assignable< json_value >::value) |
| | exchanges the values More...
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| void | swap (array_t &other) |
| | exchanges the values More...
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| void | swap (object_t &other) |
| | exchanges the values More...
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| void | swap (string_t &other) |
| | exchanges the values More...
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| bool | operator== (const_reference lhs, const_reference rhs) noexcept |
| | comparison: equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator== (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator== (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: equal More...
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| bool | operator!= (const_reference lhs, const_reference rhs) noexcept |
| | comparison: not equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator!= (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: not equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator!= (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: not equal More...
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| bool | operator< (const_reference lhs, const_reference rhs) noexcept |
| | comparison: less than More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator< (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: less than More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator< (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: less than More...
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| bool | operator<= (const_reference lhs, const_reference rhs) noexcept |
| | comparison: less than or equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator<= (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: less than or equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator<= (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: less than or equal More...
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| bool | operator> (const_reference lhs, const_reference rhs) noexcept |
| | comparison: greater than More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator> (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: greater than More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator> (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: greater than More...
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| bool | operator>= (const_reference lhs, const_reference rhs) noexcept |
| | comparison: greater than or equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator>= (const_reference lhs, const ScalarType rhs) noexcept |
| | comparison: greater than or equal More...
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| template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0> |
| bool | operator>= (const ScalarType lhs, const_reference rhs) noexcept |
| | comparison: greater than or equal More...
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| std::istream & | operator<< (basic_json &j, std::istream &i) |
| | deserialize from stream More...
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| std::istream & | operator>> (std::istream &i, basic_json &j) |
| | deserialize from stream More...
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static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | parse (detail::input_adapter &&i, const parser_callback_t cb=nullptr, const bool allow_exceptions=true) |
| | deserialize from a compatible input More...
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| static bool | accept (detail::input_adapter &&i) |
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| template<typename SAX > |
| static bool | sax_parse (detail::input_adapter &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true) |
| | generate SAX events More...
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| template<class IteratorType , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0> |
| static basic_json | parse (IteratorType first, IteratorType last, const parser_callback_t cb=nullptr, const bool allow_exceptions=true) |
| | deserialize from an iterator range with contiguous storage More...
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| template<class IteratorType , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0> |
| static bool | accept (IteratorType first, IteratorType last) |
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| template<class IteratorType , class SAX , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0> |
| static bool | sax_parse (IteratorType first, IteratorType last, SAX *sax) |
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| static std::vector< uint8_t > | to_cbor (const basic_json &j) |
| | create a CBOR serialization of a given JSON value More...
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| static void | to_cbor (const basic_json &j, detail::output_adapter< uint8_t > o) |
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| static void | to_cbor (const basic_json &j, detail::output_adapter< char > o) |
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| static std::vector< uint8_t > | to_msgpack (const basic_json &j) |
| | create a MessagePack serialization of a given JSON value More...
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| static void | to_msgpack (const basic_json &j, detail::output_adapter< uint8_t > o) |
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| static void | to_msgpack (const basic_json &j, detail::output_adapter< char > o) |
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| static std::vector< uint8_t > | to_ubjson (const basic_json &j, const bool use_size=false, const bool use_type=false) |
| | create a UBJSON serialization of a given JSON value More...
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| static void | to_ubjson (const basic_json &j, detail::output_adapter< uint8_t > o, const bool use_size=false, const bool use_type=false) |
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| static void | to_ubjson (const basic_json &j, detail::output_adapter< char > o, const bool use_size=false, const bool use_type=false) |
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| static std::vector< uint8_t > | to_bson (const basic_json &j) |
| | Serializes the given JSON object j to BSON and returns a vector containing the corresponding BSON-representation. More...
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| static void | to_bson (const basic_json &j, detail::output_adapter< uint8_t > o) |
| | Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o. More...
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| static void | to_bson (const basic_json &j, detail::output_adapter< char > o) |
| | Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o. More...
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static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_cbor (detail::input_adapter &&i, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in CBOR format More...
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| |
| template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0> |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_cbor (A1 &&a1, A2 &&a2, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in CBOR format More...
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static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_msgpack (detail::input_adapter &&i, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in MessagePack format More...
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| |
| template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0> |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_msgpack (A1 &&a1, A2 &&a2, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in MessagePack format More...
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| |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_ubjson (detail::input_adapter &&i, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in UBJSON format More...
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| |
| template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0> |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_ubjson (A1 &&a1, A2 &&a2, const bool strict=true, const bool allow_exceptions=true) |
| | create a JSON value from an input in UBJSON format More...
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| |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_bson (detail::input_adapter &&i, const bool strict=true, const bool allow_exceptions=true) |
| | Create a JSON value from an input in BSON format. More...
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| |
| template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0> |
static
JSON_HEDLEY_WARN_UNUSED_RESULT
basic_json | from_bson (A1 &&a1, A2 &&a2, const bool strict=true, const bool allow_exceptions=true) |
| | Create a JSON value from an input in BSON format. More...
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| |
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
class nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >
a class to store JSON values
- Template Parameters
-
| ObjectType | type for JSON objects (std::map by default; will be used in object_t) |
| ArrayType | type for JSON arrays (std::vector by default; will be used in array_t) |
| StringType | type for JSON strings and object keys (std::string by default; will be used in string_t) |
| BooleanType | type for JSON booleans (bool by default; will be used in boolean_t) |
| NumberIntegerType | type for JSON integer numbers (int64_t by default; will be used in number_integer_t) |
| NumberUnsignedType | type for JSON unsigned integer numbers (uint64_t |
| NumberFloatType | type for JSON floating-point numbers (double by default; will be used in number_float_t) |
| AllocatorType | type of the allocator to use (std::allocator by default) |
| JSONSerializer | the serializer to resolve internal calls to to_json() and from_json() (adl_serializer by default) |
The class satisfies the following concept requirements:
- Basic
- Layout
- StandardLayoutType: JSON values have standard layout: All non-static data members are private and standard layout types, the class has no virtual functions or (virtual) base classes.
- Library-wide
- EqualityComparable: JSON values can be compared with
==, see operator==(const_reference,const_reference).
- LessThanComparable: JSON values can be compared with
<, see operator<(const_reference,const_reference).
- Swappable: Any JSON lvalue or rvalue of can be swapped with any lvalue or rvalue of other compatible types, using unqualified function call swap().
- NullablePointer: JSON values can be compared against
std::nullptr_t objects which are used to model the null value.
- Container
- Container: JSON values can be used like STL containers and provide iterator access.
- ReversibleContainer; JSON values can be used like STL containers and provide reverse iterator access.
- Invariant
- The member variables m_value and m_type have the following relationship:
- See Also
- RFC 7159: The JavaScript Object Notation (JSON) Data Interchange Format
- Since
- version 1.0.0
Definition at line 2421 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
a type for an array
RFC 7159 describes JSON arrays as follows:
An array is an ordered sequence of zero or more values.
To store objects in C++, a type is defined by the template parameters explained below.
- Template Parameters
-
| ArrayType | container type to store arrays (e.g., std::vector or std::list) |
| AllocatorType | allocator to use for arrays (e.g., std::allocator) |
Default type
With the default values for ArrayType (std::vector) and AllocatorType (std::allocator), the default value for array_t is:
std::allocator<basic_json>
>
Limits
RFC 7159 specifies:
An implementation may set limits on the maximum depth of nesting.
In this class, the array's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the max_size function of a JSON array.
Storage
Arrays are stored as pointers in a basic_json type. That is, for any access to array values, a pointer of type array_t* must be dereferenced.
- See Also
- object_t – type for an object value
- Since
- version 1.0.0
Definition at line 15072 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::boolean_t = BooleanType |
a type for a boolean
RFC 7159 implicitly describes a boolean as a type which differentiates the two literals true and false.
To store objects in C++, a type is defined by the template parameter BooleanType which chooses the type to use.
Default type
With the default values for BooleanType (bool), the default value for boolean_t is:
Storage
Boolean values are stored directly inside a basic_json type.
- Since
- version 1.0.0
Definition at line 15151 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
the type of an element const pointer
Definition at line 14817 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
the type of an element const reference
Definition at line 14804 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::difference_type = std::ptrdiff_t |
a type to represent differences between iterators
Definition at line 14807 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
how to treat decoding errors
Definition at line 14757 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
general exception of the basic_json class
This class is an extension of std::exception objects with a member id for exception ids. It is used as the base class for all exceptions thrown by the basic_json class. This class can hence be used as "wildcard" to catch exceptions.
Subclasses:
- parse_error for exceptions indicating a parse error
- invalid_iterator for exceptions indicating errors with iterators
- type_error for exceptions indicating executing a member function with a wrong type
- out_of_range for exceptions indicating access out of the defined range
- other_error for exceptions indicating other library errors
{The following code shows how arbitrary library exceptions can be caught.,exception}
- Since
- version 3.0.0
Definition at line 14774 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
exception indicating errors with iterators
This exception is thrown if iterators passed to a library function do not match the expected semantics.
Exceptions have ids 2xx.
| name / id | example message | description |
| json.exception.invalid_iterator.201 | iterators are not compatible | The iterators passed to constructor basic_json(InputIT first, InputIT last) are not compatible, meaning they do not belong to the same container. Therefore, the range (first, last) is invalid. |
| json.exception.invalid_iterator.202 | iterator does not fit current value | In an erase or insert function, the passed iterator pos does not belong to the JSON value for which the function was called. It hence does not define a valid position for the deletion/insertion. |
| json.exception.invalid_iterator.203 | iterators do not fit current value | Either iterator passed to function erase(IteratorType first, IteratorType last) does not belong to the JSON value from which values shall be erased. It hence does not define a valid range to delete values from. |
| json.exception.invalid_iterator.204 | iterators out of range | When an iterator range for a primitive type (number, boolean, or string) is passed to a constructor or an erase function, this range has to be exactly (begin(), end()), because this is the only way the single stored value is expressed. All other ranges are invalid. |
| json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the begin() iterator, because it is the only way to address the stored value. All other iterators are invalid. |
| json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range. |
| json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key. |
| json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. |
| json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered. |
| json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (first, last) is invalid. |
| json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to. |
| json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container. |
| json.exception.invalid_iterator.213 | cannot compare order of object iterators | The order of object iterators cannot be compared, because JSON objects are unordered. |
| json.exception.invalid_iterator.214 | cannot get value | Cannot get value for iterator: Either the iterator belongs to a null value or it is an iterator to a primitive type (number, boolean, or string), but the iterator is different to begin(). |
{The following code shows how an invalid_iterator exception can be caught.,invalid_iterator}
- See Also
- - exception for the base class of the library exceptions
-
- parse_error for exceptions indicating a parse error
-
- type_error for exceptions indicating executing a member function with a wrong type
-
- out_of_range for exceptions indicating access out of the defined range
-
- other_error for exceptions indicating other library errors
- Since
- version 3.0.0
Definition at line 14778 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename T , typename SFINAE >
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::json_serializer = JSONSerializer<T, SFINAE> |
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::number_float_t = NumberFloatType |
a type for a number (floating-point)
RFC 7159 describes numbers as follows:
The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.
This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.
To store floating-point numbers in C++, a type is defined by the template parameter NumberFloatType which chooses the type to use.
Default type
With the default values for NumberFloatType (double), the default value for number_float_t is:
Default behavior
- The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in floating-point literals will be ignored. Internally, the value will be stored as decimal number. For instance, the C++ floating-point literal
01.2 will be serialized to 1.2. During deserialization, leading zeros yield an error.
- Not-a-number (NaN) values will be serialized to
null.
Limits
RFC 7159 states:
This specification allows implementations to set limits on the range and precision of numbers accepted. Since software that implements IEEE 754-2008 binary64 (double precision) numbers is generally available and widely used, good interoperability can be achieved by implementations that expect no more precision or range than these provide, in the sense that implementations will approximate JSON numbers within the expected precision.
This implementation does exactly follow this approach, as it uses double precision floating-point numbers. Note values smaller than -1.79769313486232e+308 and values greater than 1.79769313486232e+308 will be stored as NaN internally and be serialized to null.
Storage
Floating-point number values are stored directly inside a basic_json type.
- See Also
- number_integer_t – type for number values (integer)
-
number_unsigned_t – type for number values (unsigned integer)
- Since
- version 1.0.0
Definition at line 15362 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::number_integer_t = NumberIntegerType |
a type for a number (integer)
RFC 7159 describes numbers as follows:
The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.
This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.
To store integer numbers in C++, a type is defined by the template parameter NumberIntegerType which chooses the type to use.
Default type
With the default values for NumberIntegerType (int64_t), the default value for number_integer_t is:
Default behavior
- The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in integer literals lead to an interpretation as octal number. Internally, the value will be stored as decimal number. For instance, the C++ integer literal
010 will be serialized to 8. During deserialization, leading zeros yield an error.
- Not-a-number (NaN) values will be serialized to
null.
Limits
RFC 7159 specifies:
An implementation may set limits on the range and precision of numbers.
When the default type is used, the maximal integer number that can be stored is 9223372036854775807 (INT64_MAX) and the minimal integer number that can be stored is -9223372036854775808 (INT64_MIN). Integer numbers that are out of range will yield over/underflow when used in a constructor. During deserialization, too large or small integer numbers will be automatically be stored as number_unsigned_t or number_float_t.
RFC 7159 further states:
Note that when such software is used, numbers that are integers and are in the range ![$[-2^{53}+1, 2^{53}-1]$](../../form_209.png)
are interoperable in the sense that implementations will agree exactly on their numeric values.
As this range is a subrange of the exactly supported range [INT64_MIN, INT64_MAX], this class's integer type is interoperable.
Storage
Integer number values are stored directly inside a basic_json type.
- See Also
- number_float_t – type for number values (floating-point)
-
number_unsigned_t – type for number values (unsigned integer)
- Since
- version 1.0.0
Definition at line 15223 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::number_unsigned_t = NumberUnsignedType |
a type for a number (unsigned)
RFC 7159 describes numbers as follows:
The representation of numbers is similar to that used in most programming languages. A number is represented in base 10 using decimal digits. It contains an integer component that may be prefixed with an optional minus sign, which may be followed by a fraction part and/or an exponent part. Leading zeros are not allowed. (...) Numeric values that cannot be represented in the grammar below (such as Infinity and NaN) are not permitted.
This description includes both integer and floating-point numbers. However, C++ allows more precise storage if it is known whether the number is a signed integer, an unsigned integer or a floating-point number. Therefore, three different types, number_integer_t, number_unsigned_t and number_float_t are used.
To store unsigned integer numbers in C++, a type is defined by the template parameter NumberUnsignedType which chooses the type to use.
Default type
With the default values for NumberUnsignedType (uint64_t), the default value for number_unsigned_t is:
Default behavior
- The restrictions about leading zeros is not enforced in C++. Instead, leading zeros in integer literals lead to an interpretation as octal number. Internally, the value will be stored as decimal number. For instance, the C++ integer literal
010 will be serialized to 8. During deserialization, leading zeros yield an error.
- Not-a-number (NaN) values will be serialized to
null.
Limits
RFC 7159 specifies:
An implementation may set limits on the range and precision of numbers.
When the default type is used, the maximal integer number that can be stored is 18446744073709551615 (UINT64_MAX) and the minimal integer number that can be stored is 0. Integer numbers that are out of range will yield over/underflow when used in a constructor. During deserialization, too large or small integer numbers will be automatically be stored as number_integer_t or number_float_t.
RFC 7159 further states:
Note that when such software is used, numbers that are integers and are in the range are interoperable in the sense that implementations will agree exactly on their numeric values.
As this range is a subrange (when considered in conjunction with the number_integer_t type) of the exactly supported range [0, UINT64_MAX], this class's integer type is interoperable.
Storage
Integer number values are stored directly inside a basic_json type.
- See Also
- number_float_t – type for number values (floating-point)
-
number_integer_t – type for number values (integer)
- Since
- version 2.0.0
Definition at line 15294 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::object_t = ObjectType<StringType, basic_json, object_comparator_t, AllocatorType<std::pair<const StringType, basic_json>>> |
a type for an object
RFC 7159 describes JSON objects as follows:
An object is an unordered collection of zero or more name/value pairs, where a name is a string and a value is a string, number, boolean, null, object, or array.
To store objects in C++, a type is defined by the template parameters described below.
- Template Parameters
-
| ObjectType | the container to store objects (e.g., std::map or std::unordered_map) |
| StringType | the type of the keys or names (e.g., std::string). The comparison function std::less<StringType> is used to order elements inside the container. |
| AllocatorType | the allocator to use for objects (e.g., std::allocator) |
Default type
With the default values for ObjectType (std::map), StringType (std::string), and AllocatorType (std::allocator), the default value for object_t is:
std::map<
std::string,
std::less<std::string>,
std::allocator<std::pair<const std::string, basic_json>>
>
Behavior
The choice of object_t influences the behavior of the JSON class. With the default type, objects have the following behavior:
- When all names are unique, objects will be interoperable in the sense that all software implementations receiving that object will agree on the name-value mappings.
- When the names within an object are not unique, it is unspecified which one of the values for a given key will be chosen. For instance,
{"key": 2, "key": 1} could be equal to either {"key": 1} or {"key": 2}.
- Internally, name/value pairs are stored in lexicographical order of the names. Objects will also be serialized (see dump) in this order. For instance,
{"b": 1, "a": 2} and {"a": 2, "b": 1} will be stored and serialized as {"a": 2, "b": 1}.
- When comparing objects, the order of the name/value pairs is irrelevant. This makes objects interoperable in the sense that they will not be affected by these differences. For instance,
{"b": 1, "a": 2} and {"a": 2, "b": 1} will be treated as equal.
Limits
RFC 7159 specifies:
An implementation may set limits on the maximum depth of nesting.
In this class, the object's limit of nesting is not explicitly constrained. However, a maximum depth of nesting may be introduced by the compiler or runtime environment. A theoretical limit can be queried by calling the max_size function of a JSON object.
Storage
Objects are stored as pointers in a basic_json type. That is, for any access to object values, a pointer of type object_t* must be dereferenced.
- See Also
- array_t – type for an array value
- Since
- version 1.0.0
- Note
- The order name/value pairs are added to the object is not preserved by the library. Therefore, iterating an object may return name/value pairs in a different order than they were originally stored. In fact, keys will be traversed in alphabetical order as
std::map with std::less is used by default. Please note this behavior conforms to RFC 7159, because any order implements the specified "unordered" nature of JSON objects.
Definition at line 15026 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
exception indicating other library errors
This exception is thrown in case of errors that cannot be classified with the other exception types.
Exceptions have ids 5xx.
| name / id | example message | description |
| json.exception.other_error.501 | unsuccessful: {"op":"test","path":"/baz", "value":"bar"} | A JSON Patch operation 'test' failed. The unsuccessful operation is also printed. |
- See Also
- - exception for the base class of the library exceptions
-
- parse_error for exceptions indicating a parse error
-
- invalid_iterator for exceptions indicating errors with iterators
-
- type_error for exceptions indicating executing a member function with a wrong type
-
- out_of_range for exceptions indicating access out of the defined range
{The following code shows how an other_error exception can be caught.,other_error}
- Since
- version 3.0.0
Definition at line 14784 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
exception indicating access out of the defined range
This exception is thrown in case a library function is called on an input parameter that exceeds the expected range, for instance in case of array indices or nonexisting object keys.
Exceptions have ids 4xx.
| name / id | example message | description |
| json.exception.out_of_range.401 | array index 3 is out of range | The provided array index i is larger than size-1. |
| json.exception.out_of_range.402 | array index '-' (3) is out of range | The special array index - in a JSON Pointer never describes a valid element of the array, but the index past the end. That is, it can only be used to add elements at this position, but not to read it. |
| json.exception.out_of_range.403 | key 'foo' not found | The provided key was not found in the JSON object. |
| json.exception.out_of_range.404 | unresolved reference token 'foo' | A reference token in a JSON Pointer could not be resolved. |
| json.exception.out_of_range.405 | JSON pointer has no parent | The JSON Patch operations 'remove' and 'add' can not be applied to the root element of the JSON value. |
| json.exception.out_of_range.406 | number overflow parsing '10E1000' | A parsed number could not be stored as without changing it to NaN or INF. |
| json.exception.out_of_range.407 | number overflow serializing '9223372036854775808' | UBJSON and BSON only support integer numbers up to 9223372036854775807. |
| json.exception.out_of_range.408 | excessive array size: 8658170730974374167 | The size (following #) of an UBJSON array or object exceeds the maximal capacity. |
| json.exception.out_of_range.409 | BSON key cannot contain code point U+0000 (at byte 2) | Key identifiers to be serialized to BSON cannot contain code point U+0000, since the key is stored as zero-terminated c-string |
{The following code shows how an out_of_range exception can be caught.,out_of_range}
- See Also
- - exception for the base class of the library exceptions
-
- parse_error for exceptions indicating a parse error
-
- invalid_iterator for exceptions indicating errors with iterators
-
- type_error for exceptions indicating executing a member function with a wrong type
-
- other_error for exceptions indicating other library errors
- Since
- version 3.0.0
Definition at line 14782 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
exception indicating a parse error
This exception is thrown by the library when a parse error occurs. Parse errors can occur during the deserialization of JSON text, CBOR, MessagePack, as well as when using JSON Patch.
Member byte holds the byte index of the last read character in the input file.
Exceptions have ids 1xx.
| name / id | example message | description |
| json.exception.parse_error.101 | parse error at 2: unexpected end of input; expected string literal | This error indicates a syntax error while deserializing a JSON text. The error message describes that an unexpected token (character) was encountered, and the member byte indicates the error position. |
| json.exception.parse_error.102 | parse error at 14: missing or wrong low surrogate | JSON uses the \uxxxx format to describe Unicode characters. Code points above above 0xFFFF are split into two \uxxxx entries ("surrogate pairs"). This error indicates that the surrogate pair is incomplete or contains an invalid code point. |
| json.exception.parse_error.103 | parse error: code points above 0x10FFFF are invalid | Unicode supports code points up to 0x10FFFF. Code points above 0x10FFFF are invalid. |
| json.exception.parse_error.104 | parse error: JSON patch must be an array of objects | RFC 6902 requires a JSON Patch document to be a JSON document that represents an array of objects. |
| json.exception.parse_error.105 | parse error: operation must have string member 'op' | An operation of a JSON Patch document must contain exactly one "op" member, whose value indicates the operation to perform. Its value must be one of "add", "remove", "replace", "move", "copy", or "test"; other values are errors. |
| json.exception.parse_error.106 | parse error: array index '01' must not begin with '0' | An array index in a JSON Pointer (RFC 6901) may be 0 or any number without a leading 0. |
| json.exception.parse_error.107 | parse error: JSON pointer must be empty or begin with '/' - was: 'foo' | A JSON Pointer must be a Unicode string containing a sequence of zero or more reference tokens, each prefixed by a / character. |
| json.exception.parse_error.108 | parse error: escape character '~' must be followed with '0' or '1' | In a JSON Pointer, only ~0 and ~1 are valid escape sequences. |
| json.exception.parse_error.109 | parse error: array index 'one' is not a number | A JSON Pointer array index must be a number. |
| json.exception.parse_error.110 | parse error at 1: cannot read 2 bytes from vector | When parsing CBOR or MessagePack, the byte vector ends before the complete value has been read. |
| json.exception.parse_error.112 | parse error at 1: error reading CBOR; last byte: 0xF8 | Not all types of CBOR or MessagePack are supported. This exception occurs if an unsupported byte was read. |
| json.exception.parse_error.113 | parse error at 2: expected a CBOR string; last byte: 0x98 | While parsing a map key, a value that is not a string has been read. |
| json.exception.parse_error.114 | parse error: Unsupported BSON record type 0x0F | The parsing of the corresponding BSON record type is not implemented (yet). |
- Note
- For an input with n bytes, 1 is the index of the first character and n+1 is the index of the terminating null byte or the end of file. This also holds true when reading a byte vector (CBOR or MessagePack).
{The following code shows how a parse_error exception can be caught.,parse_error}
- See Also
- - exception for the base class of the library exceptions
-
- invalid_iterator for exceptions indicating errors with iterators
-
- type_error for exceptions indicating executing a member function with a wrong type
-
- out_of_range for exceptions indicating access out of the defined range
-
- other_error for exceptions indicating other library errors
- Since
- version 3.0.0
Definition at line 14776 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
parser event types
The parser callback distinguishes the following events:
object_start: the parser read { and started to process a JSON objectkey: the parser read a key of a value in an objectobject_end: the parser read } and finished processing a JSON objectarray_start: the parser read [ and started to process a JSON arrayarray_end: the parser read ] and finished processing a JSON arrayvalue: the parser finished reading a JSON value
Example when certain parse events are triggered
- See Also
- parser_callback_t for more information and examples
Definition at line 15661 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
per-element parser callback type
With a parser callback function, the result of parsing a JSON text can be influenced. When passed to parse, it is called on certain events (passed as parse_event_t via parameter event) with a set recursion depth depth and context JSON value parsed. The return value of the callback function is a boolean indicating whether the element that emitted the callback shall be kept or not.
We distinguish six scenarios (determined by the event type) in which the callback function can be called. The following table describes the values of the parameters depth, event, and parsed.
| parameter event | description | parameter depth | parameter parsed |
| parse_event_t::object_start | the parser read { and started to process a JSON object | depth of the parent of the JSON object | a JSON value with type discarded |
| parse_event_t::key | the parser read a key of a value in an object | depth of the currently parsed JSON object | a JSON string containing the key |
| parse_event_t::object_end | the parser read } and finished processing a JSON object | depth of the parent of the JSON object | the parsed JSON object |
| parse_event_t::array_start | the parser read [ and started to process a JSON array | depth of the parent of the JSON array | a JSON value with type discarded |
| parse_event_t::array_end | the parser read ] and finished processing a JSON array | depth of the parent of the JSON array | the parsed JSON array |
| parse_event_t::value | the parser finished reading a JSON value | depth of the value | the parsed JSON value |
Example when certain parse events are triggered
Discarding a value (i.e., returning false) has different effects depending on the context in which function was called:
- Discarded values in structured types are skipped. That is, the parser will behave as if the discarded value was never read.
- In case a value outside a structured type is skipped, it is replaced with
null. This case happens if the top-level element is skipped.
- Parameters
-
| [in] | depth | the depth of the recursion during parsing |
| [in] | event | an event of type parse_event_t indicating the context in the callback function has been called |
| [in,out] | parsed | the current intermediate parse result; note that writing to this value has no effect for parse_event_t::key events |
- Returns
- Whether the JSON value which called the function during parsing should be kept (
true) or not (false). In the latter case, it is either skipped completely or replaced by an empty discarded object.
- See Also
- parse for examples
- Since
- version 1.0.0
Definition at line 15712 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
the type of an element pointer
Definition at line 14815 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
the type of an element reference
Definition at line 14802 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::size_type = std::size_t |
a type to represent container sizes
Definition at line 14809 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| using nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::string_t = StringType |
a type for a string
RFC 7159 describes JSON strings as follows:
A string is a sequence of zero or more Unicode characters.
To store objects in C++, a type is defined by the template parameter described below. Unicode values are split by the JSON class into byte-sized characters during deserialization.
- Template Parameters
-
| StringType | the container to store strings (e.g., std::string). Note this container is used for keys/names in objects, see object_t. |
Default type
With the default values for StringType (std::string), the default value for string_t is:
Encoding
Strings are stored in UTF-8 encoding. Therefore, functions like std::string::size() or std::string::length() return the number of bytes in the string rather than the number of characters or glyphs.
String comparison
RFC 7159 states:
Software implementations are typically required to test names of object members for equality. Implementations that transform the textual representation into sequences of Unicode code units and then perform the comparison numerically, code unit by code unit, are interoperable in the sense that implementations will agree in all cases on equality or inequality of two strings. For example, implementations that compare strings with escaped characters unconverted may incorrectly find that "a\\\\b" and "a\\u005Cb" are not equal.
This implementation is interoperable as it does compare strings code unit by code unit.
Storage
String values are stored as pointers in a basic_json type. That is, for any access to string values, a pointer of type string_t* must be dereferenced.
- Since
- version 1.0.0
Definition at line 15125 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
exception indicating executing a member function with a wrong type
This exception is thrown in case of a type error; that is, a library function is executed on a JSON value whose type does not match the expected semantics.
Exceptions have ids 3xx.
| name / id | example message | description |
| json.exception.type_error.301 | cannot create object from initializer list | To create an object from an initializer list, the initializer list must consist only of a list of pairs whose first element is a string. When this constraint is violated, an array is created instead. |
| json.exception.type_error.302 | type must be object, but is array | During implicit or explicit value conversion, the JSON type must be compatible to the target type. For instance, a JSON string can only be converted into string types, but not into numbers or boolean types. |
| json.exception.type_error.303 | incompatible ReferenceType for get_ref, actual type is object | To retrieve a reference to a value stored in a basic_json object with get_ref, the type of the reference must match the value type. For instance, for a JSON array, the ReferenceType must be array_t &. |
| json.exception.type_error.304 | cannot use at() with string | The at() member functions can only be executed for certain JSON types. |
| json.exception.type_error.305 | cannot use operator[] with string | The operator[] member functions can only be executed for certain JSON types. |
| json.exception.type_error.306 | cannot use value() with string | The value() member functions can only be executed for certain JSON types. |
| json.exception.type_error.307 | cannot use erase() with string | The erase() member functions can only be executed for certain JSON types. |
| json.exception.type_error.308 | cannot use push_back() with string | The push_back() and operator+= member functions can only be executed for certain JSON types. |
| json.exception.type_error.309 | cannot use insert() with | The insert() member functions can only be executed for certain JSON types. |
| json.exception.type_error.310 | cannot use swap() with number | The swap() member functions can only be executed for certain JSON types. |
| json.exception.type_error.311 | cannot use emplace_back() with string | The emplace_back() member function can only be executed for certain JSON types. |
| json.exception.type_error.312 | cannot use update() with string | The update() member functions can only be executed for certain JSON types. |
| json.exception.type_error.313 | invalid value to unflatten | The unflatten function converts an object whose keys are JSON Pointers back into an arbitrary nested JSON value. The JSON Pointers must not overlap, because then the resulting value would not be well defined. |
| json.exception.type_error.314 | only objects can be unflattened | The unflatten function only works for an object whose keys are JSON Pointers. |
| json.exception.type_error.315 | values in object must be primitive | The unflatten function only works for an object whose keys are JSON Pointers and whose values are primitive. |
| json.exception.type_error.316 | invalid UTF-8 byte at index 10: 0x7E | The dump function only works with UTF-8 encoded strings; that is, if you assign a std::string to a JSON value, make sure it is UTF-8 encoded. |
| json.exception.type_error.317 | JSON value cannot be serialized to requested format | The dynamic type of the object cannot be represented in the requested serialization format (e.g. a raw true or null JSON object cannot be serialized to BSON) |
{The following code shows how a type_error exception can be caught.,type_error}
- See Also
- - exception for the base class of the library exceptions
-
- parse_error for exceptions indicating a parse error
-
- invalid_iterator for exceptions indicating errors with iterators
-
- out_of_range for exceptions indicating access out of the defined range
-
- other_error for exceptions indicating other library errors
- Since
- version 3.0.0
Definition at line 14780 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
const value_t |
v | ) |
|
|
inline |
create an empty value with a given type
Create an empty JSON value with a given type. The value will be default initialized with an empty value which depends on the type:
| Value type | initial value |
| null | null |
| boolean | false |
| string | "" |
| number | 0 |
| object | {} |
| array | [] |
- Parameters
-
| [in] | v | the type of the value to create |
Constant.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The following code shows the constructor for different value_t values,basic_json__value_t}
- See Also
- clear() – restores the postcondition of this constructor
- Since
- version 1.0.0
Definition at line 15752 of file json.hpp.
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
std::nullptr_t |
= nullptr | ) |
|
|
inlinenoexcept |
create a null object
Create a null JSON value. It either takes a null pointer as parameter (explicitly creating null) or no parameter (implicitly creating null). The passed null pointer itself is not read – it is only used to choose the right constructor.
Constant.
No-throw guarantee: this constructor never throws exceptions.
{The following code shows the constructor with and without a null pointer parameter.,basic_json__nullptr_t}
- Since
- version 1.0.0
Definition at line 15776 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
void assert_invariant() const noexcept
checks the class invariants
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename CompatibleType , typename U = detail::uncvref_t<CompatibleType>, detail::enable_if_t< not detail::is_basic_json< U >::value and detail::is_compatible_type< basic_json_t, U >::value, int > = 0>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
CompatibleType && |
val | ) |
|
|
inlinenoexcept |
create a JSON value
This is a "catch all" constructor for all compatible JSON types; that is, types for which a to_json() method exists. The constructor forwards the parameter val to that method (to json_serializer<U>::to_json method with U = uncvref_t<CompatibleType>, to be exact).
Template type CompatibleType includes, but is not limited to, the following types:
- arrays: array_t and all kinds of compatible containers such as
std::vector, std::deque, std::list, std::forward_list, std::array, std::valarray, std::set, std::unordered_set, std::multiset, and std::unordered_multiset with a value_type from which a basic_json value can be constructed.
- objects: object_t and all kinds of compatible associative containers such as
std::map, std::unordered_map, std::multimap, and std::unordered_multimap with a key_type compatible to string_t and a value_type from which a basic_json value can be constructed.
- strings: string_t, string literals, and all compatible string containers can be used.
- numbers: number_integer_t, number_unsigned_t, number_float_t, and all convertible number types such as
int, size_t, int64_t, float or double can be used.
- boolean: boolean_t /
bool can be used.
See the examples below.
- Template Parameters
-
| CompatibleType | a type such that:
- CompatibleType is not derived from
std::istream,
- CompatibleType is not basic_json (to avoid hijacking copy/move constructors),
- CompatibleType is not a different basic_json type (i.e. with different template arguments)
- CompatibleType is not a basic_json nested type (e.g., json_pointer, iterator, etc ...)
- json_serializer<U> has a
to_json(basic_json_t&, CompatibleType&&) method
|
| U | = uncvref_t<CompatibleType> |
- Parameters
-
| [in] | val | the value to be forwarded to the respective constructor |
Usually linear in the size of the passed val, also depending on the implementation of the called to_json() method.
Depends on the called constructor. For types directly supported by the library (i.e., all types for which no to_json() function was provided), strong guarantee holds: if an exception is thrown, there are no changes to any JSON value.
{The following code shows the constructor with several compatible types.,basic_json__CompatibleType}
- Since
- version 2.1.0
Definition at line 15843 of file json.hpp.
void to_json(BasicJsonType &j, T b) noexcept
void assert_invariant() const noexcept
checks the class invariants
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType , detail::enable_if_t< detail::is_basic_json< BasicJsonType >::value and not std::is_same< basic_json, BasicJsonType >::value, int > = 0>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
const BasicJsonType & |
val | ) |
|
|
inline |
create a JSON value from an existing one
This is a constructor for existing basic_json types. It does not hijack copy/move constructors, since the parameter has different template arguments than the current ones.
The constructor tries to convert the internal m_value of the parameter.
- Template Parameters
-
| BasicJsonType | a type such that:
|
- Parameters
-
Usually linear in the size of the passed val, also depending on the implementation of the called to_json() method.
Depends on the called constructor. For types directly supported by the library (i.e., all types for which no to_json() function was provided), strong guarantee holds: if an exception is thrown, there are no changes to any JSON value.
- Since
- version 3.2.0
Definition at line 15880 of file json.hpp.
15882 using other_boolean_t =
typename BasicJsonType::boolean_t;
15883 using other_number_float_t =
typename BasicJsonType::number_float_t;
15884 using other_number_integer_t =
typename BasicJsonType::number_integer_t;
15885 using other_number_unsigned_t =
typename BasicJsonType::number_unsigned_t;
15886 using other_string_t =
typename BasicJsonType::string_t;
15887 using other_object_t =
typename BasicJsonType::object_t;
15888 using other_array_t =
typename BasicJsonType::array_t;
15890 switch (val.type())
array (ordered collection of values)
number value (signed integer)
void to_json(BasicJsonType &j, T b) noexcept
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
number value (unsigned integer)
number value (floating-point)
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
initializer_list_t |
init, |
|
|
bool |
type_deduction = true, |
|
|
value_t |
manual_type = value_t::array |
|
) |
| |
|
inline |
create a container (array or object) from an initializer list
Creates a JSON value of type array or object from the passed initializer list init. In case type_deduction is true (default), the type of the JSON value to be created is deducted from the initializer list init according to the following rules:
- If the list is empty, an empty JSON object value
{} is created.
- If the list consists of pairs whose first element is a string, a JSON object value is created where the first elements of the pairs are treated as keys and the second elements are as values.
- In all other cases, an array is created.
The rules aim to create the best fit between a C++ initializer list and JSON values. The rationale is as follows:
- The empty initializer list is written as
{} which is exactly an empty JSON object.
- C++ has no way of describing mapped types other than to list a list of pairs. As JSON requires that keys must be of type string, rule 2 is the weakest constraint one can pose on initializer lists to interpret them as an object.
- In all other cases, the initializer list could not be interpreted as JSON object type, so interpreting it as JSON array type is safe.
With the rules described above, the following JSON values cannot be expressed by an initializer list:
- Note
- When used without parentheses around an empty initializer list, basic_json() is called instead of this function, yielding the JSON null value.
- Parameters
-
| [in] | init | initializer list with JSON values |
| [in] | type_deduction | internal parameter; when set to true, the type of the JSON value is deducted from the initializer list init; when set to false, the type provided via manual_type is forced. This mode is used by the functions array(initializer_list_t) and object(initializer_list_t). |
| [in] | manual_type | internal parameter; when type_deduction is set to false, the created JSON value will use the provided type (only value_t::array and value_t::object are valid); when type_deduction is set to true, this parameter has no effect |
- Exceptions
-
| type_error.301 | if type_deduction is false, manual_type is value_t::object, but init contains an element which is not a pair whose first element is a string. In this case, the constructor could not create an object. If type_deduction would have be true, an array would have been created. See object(initializer_list_t) for an example. |
Linear in the size of the initializer list init.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The example below shows how JSON values are created from initializer lists.,basic_json__list_init_t}
- See Also
- array(initializer_list_t) – create a JSON array value from an initializer list
-
object(initializer_list_t) – create a JSON object value from an initializer list
- Since
- version 1.0.0
Definition at line 15999 of file json.hpp.
16005 bool is_an_object = std::all_of(init.begin(), init.end(),
16006 [](
const detail::json_ref<basic_json>& element_ref)
16008 return element_ref->is_array()
and element_ref->size() == 2
and (*element_ref)[0].is_string();
16012 if (not type_deduction)
16017 is_an_object =
false;
16033 std::for_each(init.begin(), init.end(), [
this](
const detail::json_ref<basic_json>& element_ref)
16035 auto element = element_ref.moved_or_copied();
16037 std::move(*((*
element.m_value.array)[0].m_value.string)),
16038 std::move((*
element.m_value.array)[1]));
16045 m_value.
array = create<array_t>(init.begin(), init.end());
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
size_type |
cnt, |
|
|
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
val |
|
) |
| |
|
inline |
construct an array with count copies of given value
Constructs a JSON array value by creating cnt copies of a passed value. In case cnt is 0, an empty array is created.
- Parameters
-
| [in] | cnt | the number of JSON copies of val to create |
| [in] | val | the JSON value to copy |
- Postcondition
std::distance(begin(),end()) == cnt holds.
Linear in cnt.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The following code shows examples for the basic_json(size_type\, const basic_json&) constructor.,basic_json__size_type_basic_json}
- Since
- version 1.0.0
Definition at line 16160 of file json.hpp.
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class InputIT , typename std::enable_if< std::is_same< InputIT, typename basic_json_t::iterator >::value orstd::is_same< InputIT, typename basic_json_t::const_iterator >::value, int >::type = 0>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
InputIT |
first, |
|
|
InputIT |
last |
|
) |
| |
|
inline |
construct a JSON container given an iterator range
Constructs the JSON value with the contents of the range [first, last). The semantics depends on the different types a JSON value can have:
- In case of a null type, invalid_iterator.206 is thrown.
- In case of other primitive types (number, boolean, or string), first must be
begin() and last must be end(). In this case, the value is copied. Otherwise, invalid_iterator.204 is thrown.
- In case of structured types (array, object), the constructor behaves as similar versions for
std::vector or std::map; that is, a JSON array or object is constructed from the values in the range.
- Template Parameters
-
- Parameters
-
| [in] | first | begin of the range to copy from (included) |
| [in] | last | end of the range to copy from (excluded) |
- Precondition
- Iterators first and last must be initialized. This precondition is enforced with an assertion (see warning). If assertions are switched off, a violation of this precondition yields undefined behavior.
-
Range
[first, last) is valid. Usually, this precondition cannot be checked efficiently. Only certain edge cases are detected; see the description of the exceptions below. A violation of this precondition yields undefined behavior.
- Warning
- A precondition is enforced with a runtime assertion that will result in calling
std::abort if this precondition is not met. Assertions can be disabled by defining NDEBUG at compile time. See https://en.cppreference.com/w/cpp/error/assert for more information.
- Exceptions
-
| invalid_iterator.201 | if iterators first and last are not compatible (i.e., do not belong to the same JSON value). In this case, the range [first, last) is undefined. |
| invalid_iterator.204 | if iterators first and last belong to a primitive type (number, boolean, or string), but first does not point to the first element any more. In this case, the range [first, last) is undefined. See example code below. |
| invalid_iterator.206 | if iterators first and last belong to a null value. In this case, the range [first, last) is undefined. |
Linear in distance between first and last.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The example below shows several ways to create JSON values by specifying a subrange with iterators.,basic_json__InputIt_InputIt}
- Since
- version 1.0.0
Definition at line 16225 of file json.hpp.
16227 assert(
first.m_object !=
nullptr);
16228 assert(last.m_object !=
nullptr);
16249 or not last.m_it.primitive_iterator.is_end()))
16295 last.m_it.object_iterator);
16302 last.m_it.array_iterator);
16308 std::string(
first.m_object->type_name())));
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
number value (signed integer)
number_unsigned_t number_unsigned
number (unsigned integer)
number_float_t number_float
number (floating-point)
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
static invalid_iterator create(int id_, const std::string &what_arg)
number_integer_t number_integer
number (integer)
number value (unsigned integer)
number value (floating-point)
#define JSON_HEDLEY_UNLIKELY(expr)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
other | ) |
|
|
inline |
copy constructor
Creates a copy of a given JSON value.
- Parameters
-
| [in] | other | the JSON value to copy |
- Postcondition
*this == other
Linear in the size of other.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
This function helps basic_json satisfying the Container requirements:
- The complexity is linear.
- As postcondition, it holds:
other == basic_json(other).
{The following code shows an example for the copy constructor.,basic_json__basic_json}
- Since
- version 1.0.0
Definition at line 16349 of file json.hpp.
16353 other.assert_invariant();
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
string_t * string
string (stored with pointer to save storage)
array (ordered collection of values)
number value (signed integer)
number_unsigned_t number_unsigned
number (unsigned integer)
number_float_t number_float
number (floating-point)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
number_integer_t number_integer
number (integer)
number value (unsigned integer)
number value (floating-point)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::basic_json |
( |
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > && |
other | ) |
|
|
inlinenoexcept |
move constructor
Move constructor. Constructs a JSON value with the contents of the given value other using move semantics. It "steals" the resources from other and leaves it as JSON null value.
- Parameters
-
| [in,out] | other | value to move to this object |
- Postcondition
*this has the same value as other before the call. -
other is a JSON null value.
Constant.
No-throw guarantee: this constructor never throws exceptions.
This function helps basic_json satisfying the MoveConstructible requirements.
{The code below shows the move constructor explicitly called via std::move.,basic_json__moveconstructor}
- Since
- version 1.0.0
Definition at line 16432 of file json.hpp.
16433 :
m_type(std::move(other.m_type)),
16434 m_value(std::move(other.m_value))
16437 other.assert_invariant();
16441 other.m_value = {};
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class IteratorType , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0>
| static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::accept |
( |
IteratorType |
first, |
|
|
IteratorType |
last |
|
) |
| |
|
inlinestatic |
Definition at line 20890 of file json.hpp.
20892 return parser(detail::input_adapter(
first, last)).accept(
true);
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
explicitly create an array from an initializer list
Creates a JSON array value from a given initializer list. That is, given a list of values a, b, c, creates the JSON value [a, b, c]. If the initializer list is empty, the empty array [] is created.
- Note
- This function is only needed to express two edge cases that cannot be realized with the initializer list constructor (basic_json(initializer_list_t, bool, value_t)). These cases are:
- creating an array whose elements are all pairs whose first element is a string – in this case, the initializer list constructor would create an object, taking the first elements as keys
- creating an empty array – passing the empty initializer list to the initializer list constructor yields an empty object
- Parameters
-
| [in] | init | initializer list with JSON values to create an array from (optional) |
- Returns
- JSON array value
Linear in the size of init.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The following code shows an example for the array function.,array}
- See Also
- basic_json(initializer_list_t, bool, value_t) – create a JSON value from an initializer list
-
object(initializer_list_t) – create a JSON object value from an initializer list
- Since
- version 1.0.0
Definition at line 16089 of file json.hpp.
array (ordered collection of values)
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::assert_invariant |
( |
| ) |
const |
|
inlineprivatenoexcept |
checks the class invariants
This function asserts the class invariants. It needs to be called at the end of every constructor to make sure that created objects respect the invariant. Furthermore, it has to be called each time the type of a JSON value is changed, because the invariant expresses a relationship between m_type and m_value.
Definition at line 15634 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
string_t * string
string (stored with pointer to save storage)
array (ordered collection of values)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified array element with bounds checking
Returns a reference to the element at specified location idx, with bounds checking.
- Parameters
-
| [in] | idx | index of the element to access |
- Returns
- reference to the element at index idx
- Exceptions
-
| type_error.304 | if the JSON value is not an array; in this case, calling at with an index makes no sense. See example below. |
| out_of_range.401 | if the index idx is out of range of the array; that is, idx >= size(). See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 1.0.0
{The example below shows how array elements can be read and written using at(). It also demonstrates the different exceptions that can be thrown.,at__size_type}
Definition at line 17519 of file json.hpp.
#define JSON_CATCH(exception)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
std::string to_string(WindowPattern const &pattern)
constexpr bool is_array() const noexcept
return whether value is an array
static out_of_range create(int id_, const std::string &what_arg)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified array element with bounds checking
Returns a const reference to the element at specified location idx, with bounds checking.
- Parameters
-
| [in] | idx | index of the element to access |
- Returns
- const reference to the element at index idx
- Exceptions
-
| type_error.304 | if the JSON value is not an array; in this case, calling at with an index makes no sense. See example below. |
| out_of_range.401 | if the index idx is out of range of the array; that is, idx >= size(). See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 1.0.0
{The example below shows how array elements can be read using at(). It also demonstrates the different exceptions that can be thrown., at__size_type_const}
Definition at line 17566 of file json.hpp.
#define JSON_CATCH(exception)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
std::string to_string(WindowPattern const &pattern)
constexpr bool is_array() const noexcept
return whether value is an array
static out_of_range create(int id_, const std::string &what_arg)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::at |
( |
const typename object_t::key_type & |
key | ) |
|
|
inline |
access specified object element with bounds checking
Returns a reference to the element at with specified key key, with bounds checking.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- reference to the element at key key
- Exceptions
-
| type_error.304 | if the JSON value is not an object; in this case, calling at with a key makes no sense. See example below. |
| out_of_range.403 | if the key key is is not stored in the object; that is, find(key) == end(). See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Logarithmic in the size of the container.
- See Also
- operator[](const typename object_t::key_type&) for unchecked access by reference
-
value() for access by value with a default value
- Since
- version 1.0.0
{The example below shows how object elements can be read and written using at(). It also demonstrates the different exceptions that can be thrown.,at__object_t_key_type}
Definition at line 17617 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
#define JSON_CATCH(exception)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static out_of_range create(int id_, const std::string &what_arg)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::at |
( |
const typename object_t::key_type & |
key | ) |
const |
|
inline |
access specified object element with bounds checking
Returns a const reference to the element at with specified key key, with bounds checking.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- const reference to the element at key key
- Exceptions
-
| type_error.304 | if the JSON value is not an object; in this case, calling at with a key makes no sense. See example below. |
| out_of_range.403 | if the key key is is not stored in the object; that is, find(key) == end(). See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Logarithmic in the size of the container.
- See Also
- operator[](const typename object_t::key_type&) for unchecked access by reference
-
value() for access by value with a default value
- Since
- version 1.0.0
{The example below shows how object elements can be read using at(). It also demonstrates the different exceptions that can be thrown., at__object_t_key_type_const}
Definition at line 17668 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
#define JSON_CATCH(exception)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static out_of_range create(int id_, const std::string &what_arg)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified element via JSON Pointer
Returns a reference to the element at with specified JSON pointer ptr, with bounds checking.
- Parameters
-
| [in] | ptr | JSON pointer to the desired element |
- Returns
- reference to the element pointed to by ptr
- Exceptions
-
| parse_error.106 | if an array index in the passed JSON pointer ptr begins with '0'. See example below. |
| parse_error.109 | if an array index in the passed JSON pointer ptr is not a number. See example below. |
| out_of_range.401 | if an array index in the passed JSON pointer ptr is out of range. See example below. |
| out_of_range.402 | if the array index '-' is used in the passed JSON pointer ptr. As at provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. |
| out_of_range.403 | if the JSON pointer describes a key of an object which cannot be found. See example below. |
| out_of_range.404 | if the JSON pointer ptr can not be resolved. See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 2.0.0
{The behavior is shown in the example.,at_json_pointer}
Definition at line 21942 of file json.hpp.
21944 return ptr.get_checked(
this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified element via JSON Pointer
Returns a const reference to the element at with specified JSON pointer ptr, with bounds checking.
- Parameters
-
| [in] | ptr | JSON pointer to the desired element |
- Returns
- reference to the element pointed to by ptr
- Exceptions
-
| parse_error.106 | if an array index in the passed JSON pointer ptr begins with '0'. See example below. |
| parse_error.109 | if an array index in the passed JSON pointer ptr is not a number. See example below. |
| out_of_range.401 | if an array index in the passed JSON pointer ptr is out of range. See example below. |
| out_of_range.402 | if the array index '-' is used in the passed JSON pointer ptr. As at provides checked access (and no elements are implicitly inserted), the index '-' is always invalid. See example below. |
| out_of_range.403 | if the JSON pointer describes a key of an object which cannot be found. See example below. |
| out_of_range.404 | if the JSON pointer ptr can not be resolved. See example below. |
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 2.0.0
{The behavior is shown in the example.,at_json_pointer_const}
Definition at line 21985 of file json.hpp.
21987 return ptr.get_checked(
this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::back |
( |
| ) |
|
|
inline |
access the last element
Returns a reference to the last element in the container. For a JSON container c, the expression c.back() is equivalent to
auto tmp = c.end();
--tmp;
return *tmp;
- Returns
- In case of a structured type (array or object), a reference to the last element is returned. In case of number, string, or boolean values, a reference to the value is returned.
Constant.
- Precondition
- The JSON value must not be
null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).
- Postcondition
- The JSON value remains unchanged.
- Exceptions
-
| invalid_iterator.214 | when called on a null value. See example below. |
{The following code shows an example for back().,back}
- See Also
- front() – access the first element
- Since
- version 1.0.0
Definition at line 18173 of file json.hpp.
iterator end() noexcept
returns an iterator to one past the last element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::back |
( |
| ) |
const |
|
inline |
access the last element
Returns a reference to the last element in the container. For a JSON container c, the expression c.back() is equivalent to
auto tmp = c.end();
--tmp;
return *tmp;
- Returns
- In case of a structured type (array or object), a reference to the last element is returned. In case of number, string, or boolean values, a reference to the value is returned.
Constant.
- Precondition
- The JSON value must not be
null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).
- Postcondition
- The JSON value remains unchanged.
- Exceptions
-
| invalid_iterator.214 | when called on a null value. See example below. |
{The following code shows an example for back().,back}
- See Also
- front() – access the first element
- Since
- version 1.0.0
Definition at line 18183 of file json.hpp.
const_iterator cend() const noexcept
returns a const iterator to one past the last element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::begin |
( |
| ) |
|
|
inlinenoexcept |
returns an iterator to the first element
Returns an iterator to the first element.
Illustration from cppreference.com
- Returns
- iterator to the first element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
{The following code shows an example for begin().,begin}
- See Also
- cbegin() – returns a const iterator to the beginning
-
end() – returns an iterator to the end
-
cend() – returns a const iterator to the end
- Since
- version 1.0.0
Definition at line 18674 of file json.hpp.
18677 result.set_begin();
iter_impl< basic_json > iterator
an iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::begin |
( |
| ) |
const |
|
inlinenoexcept |
returns a const iterator to the first element
Returns a const iterator to the first element.
Illustration from cppreference.com
- Returns
- const iterator to the first element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).begin().
{The following code shows an example for cbegin().,cbegin}
- See Also
- begin() – returns an iterator to the beginning
-
end() – returns an iterator to the end
-
cend() – returns a const iterator to the end
- Since
- version 1.0.0
Definition at line 18684 of file json.hpp.
const_iterator cbegin() const noexcept
returns a const iterator to the first element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::cbegin |
( |
| ) |
const |
|
inlinenoexcept |
returns a const iterator to the first element
Returns a const iterator to the first element.
Illustration from cppreference.com
- Returns
- const iterator to the first element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).begin().
{The following code shows an example for cbegin().,cbegin}
- See Also
- begin() – returns an iterator to the beginning
-
end() – returns an iterator to the end
-
cend() – returns a const iterator to the end
- Since
- version 1.0.0
Definition at line 18714 of file json.hpp.
18717 result.set_begin();
iter_impl< const basic_json > const_iterator
a const iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::cend |
( |
| ) |
const |
|
inlinenoexcept |
returns a const iterator to one past the last element
Returns a const iterator to one past the last element.
Illustration from cppreference.com
- Returns
- const iterator one past the last element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).end().
{The following code shows an example for cend().,cend}
- See Also
- end() – returns an iterator to the end
-
begin() – returns an iterator to the beginning
-
cbegin() – returns a const iterator to the beginning
- Since
- version 1.0.0
Definition at line 18785 of file json.hpp.
iter_impl< const basic_json > const_iterator
a const iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::clear |
( |
| ) |
|
|
inlinenoexcept |
clears the contents
Clears the content of a JSON value and resets it to the default value as if basic_json(value_t) would have been called with the current value type from type():
| Value type | initial value |
| null | null |
| boolean | false |
| string | "" |
| number | 0 |
| object | {} |
| array | [] |
- Postcondition
- Has the same effect as calling
{The example below shows the effect of clear() to different JSON types.,clear}
Linear in the size of the JSON value.
All iterators, pointers and references related to this container are invalidated.
No-throw guarantee: this function never throws exceptions.
- See Also
- basic_json(value_t) – constructor that creates an object with the same value than calling
clear()
- Since
- version 1.0.0
Definition at line 19335 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
string_t * string
string (stored with pointer to save storage)
array (ordered collection of values)
number value (signed integer)
number_unsigned_t number_unsigned
number (unsigned integer)
number_float_t number_float
number (floating-point)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
number_integer_t number_integer
number (integer)
number value (unsigned integer)
number value (floating-point)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename KeyT , typename std::enable_if< not std::is_same< typename std::decay< KeyT >::type, json_pointer >::value, int >::type = 0>
| bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::contains |
( |
KeyT && |
key | ) |
const |
|
inline |
check the existence of an element in a JSON object
Check whether an element exists in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, false is returned.
- Note
- This method always returns false when executed on a JSON type that is not an object.
- Parameters
-
| [in] | key | key value to check its existence. |
- Returns
- true if an element with specified key exists. If no such element with such key is found or the JSON value is not an object, false is returned.
Logarithmic in the size of the JSON object.
{The following code shows an example for contains().,contains}
- See Also
- find(KeyT&&) – returns an iterator to an object element
-
contains(const json_pointer&) const – checks the existence for a JSON pointer
- Since
- version 3.6.0
Definition at line 18604 of file json.hpp.
double std(const std::vector< short > &wf, const double ped_mean, size_t start, size_t nsample)
iterator end() noexcept
returns an iterator to one past the last element
constexpr bool is_object() const noexcept
return whether value is an object
iterator find(KeyT &&key)
find an element in a JSON object
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::contains |
( |
const json_pointer & |
ptr | ) |
const |
|
inline |
check the existence of an element in a JSON object given a JSON pointer
Check whether the given JSON pointer ptr can be resolved in the current JSON value.
- Note
- This method can be executed on any JSON value type.
- Parameters
-
| [in] | ptr | JSON pointer to check its existence. |
- Returns
- true if the JSON pointer can be resolved to a stored value, false otherwise.
- Postcondition
- If
j.contains(ptr) returns true, it is safe to call j[ptr].
- Exceptions
-
| parse_error.106 | if an array index begins with '0' |
| parse_error.109 | if an array index was not a number |
Logarithmic in the size of the JSON object.
{The following code shows an example for contains().,contains_json_pointer}
- See Also
- contains(KeyT &&) const – checks the existence of a key
- Since
- version 3.7.0
Definition at line 18635 of file json.hpp.
18637 return ptr.contains(
this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename KeyT >
| size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::count |
( |
KeyT && |
key | ) |
const |
|
inline |
returns the number of occurrences of a key in a JSON object
Returns the number of elements with key key. If ObjectType is the default std::map type, the return value will always be 0 (key was not found) or 1 (key was found).
- Note
- This method always returns
0 when executed on a JSON type that is not an object.
- Parameters
-
| [in] | key | key value of the element to count |
- Returns
- Number of elements with key key. If the JSON value is not an object, the return value will be
0.
Logarithmic in the size of the JSON object.
{The example shows how count() is used.,count}
- Since
- version 1.0.0
Definition at line 18571 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
constexpr bool is_object() const noexcept
return whether value is an object
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
returns a const reverse iterator to the last element
Returns a const iterator to the reverse-beginning; that is, the last element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).rbegin().
{The following code shows an example for crbegin().,crbegin}
- See Also
- rbegin() – returns a reverse iterator to the beginning
-
rend() – returns a reverse iterator to the end
-
crend() – returns a const reverse iterator to the end
- Since
- version 1.0.0
Definition at line 18889 of file json.hpp.
json_reverse_iterator< typename basic_json::const_iterator > const_reverse_iterator
a const reverse iterator for a basic_json container
const_iterator cend() const noexcept
returns a const iterator to one past the last element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename T , typename... Args>
helper for exception-safe object creation
Definition at line 15371 of file json.hpp.
15373 AllocatorType<T> alloc;
15374 using AllocatorTraits = std::allocator_traits<AllocatorType<T>>;
15376 auto deleter = [&](T *
object)
15378 AllocatorTraits::deallocate(alloc,
object, 1);
15380 std::unique_ptr<T, decltype(deleter)>
object(AllocatorTraits::allocate(alloc, 1), deleter);
15381 AllocatorTraits::construct(alloc,
object.
get(), std::forward<Args>(
args)...);
15382 assert(
object !=
nullptr);
15383 return object.release();
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json object(initializer_list_t init={})
explicitly create an object from an initializer list
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
returns a const reverse iterator to one before the first
Returns a const reverse iterator to the reverse-end; that is, one before the first element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).rend().
{The following code shows an example for crend().,crend}
- See Also
- rend() – returns a reverse iterator to the end
-
rbegin() – returns a reverse iterator to the beginning
-
crbegin() – returns a const reverse iterator to the beginning
- Since
- version 1.0.0
Definition at line 18918 of file json.hpp.
json_reverse_iterator< typename basic_json::const_iterator > const_reverse_iterator
a const reverse iterator for a basic_json container
const_iterator cbegin() const noexcept
returns a const iterator to the first element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::diff |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
source, |
|
|
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
target, |
|
|
const std::string & |
path = "" |
|
) |
| |
|
inlinestatic |
creates a diff as a JSON patch
Creates a JSON Patch so that value source can be changed into the value target by calling patch function.
- Invariant
- For two JSON values source and target, the following code yields always
true:
- Note
- Currently, only
remove, add, and replace operations are generated.
- Parameters
-
| [in] | source | JSON value to compare from |
| [in] | target | JSON value to compare against |
| [in] | path | helper value to create JSON pointers |
- Returns
- a JSON patch to convert the source to target
Linear in the lengths of source and target.
{The following code shows how a JSON patch is created as a diff for two JSON values.,diff}
- See Also
- patch – apply a JSON patch
-
merge_patch – apply a JSON Merge Patch
-
RFC 6902 (JSON Patch)
- Since
- version 2.0.0
Definition at line 22406 of file json.hpp.
22418 if (
source.type() != target.type())
22423 {
"op",
"replace"}, {
"path",
path}, {
"value", target}
22434 while (i <
source.size()
and i < target.size())
22438 result.insert(result.end(), temp_diff.begin(), temp_diff.end());
22447 while (i <
source.size())
22451 result.insert(result.begin() + end_index,
object(
22460 while (i < target.size())
22466 {
"value", target[i]}
22477 for (
auto it =
source.cbegin(); it !=
source.cend(); ++it)
22482 if (target.find(it.key()) != target.end())
22485 auto temp_diff =
diff(it.value(), target[it.key()],
path +
"/" + key);
22486 result.
insert(result.end(), temp_diff.begin(), temp_diff.end());
22491 result.push_back(
object(
22493 {
"op",
"remove"}, {
"path",
path +
"/" + key}
22499 for (
auto it = target.cbegin(); it != target.cend(); ++it)
22507 {
"op",
"add"}, {
"path",
path +
"/" + key},
22508 {
"value", it.value()}
22521 {
"op",
"replace"}, {
"path",
path}, {
"value", target}
array (ordered collection of values)
basic_json(const value_t v)
create an empty value with a given type
static std::string escape(std::string s)
escape "~" to "~0" and "/" to "~1"
std::ptrdiff_t difference_type
a type to represent differences between iterators
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json object(initializer_list_t init={})
explicitly create an object from an initializer list
BEGIN_PROLOG triggeremu_data_config_icarus settings PMTADCthresholds sequence::icarus_stage0_multiTPC_TPC physics sequence::icarus_stage0_EastHits_TPC physics sequence::icarus_stage0_WestHits_TPC physics producers purityana0 caloskimCalorimetryCryoE physics caloskimCalorimetryCryoW physics path
object (unordered set of name/value pairs)
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json diff(const basic_json &source, const basic_json &target, const std::string &path="")
creates a diff as a JSON patch
std::string to_string(WindowPattern const &pattern)
iterator insert(const_iterator pos, const basic_json &val)
inserts element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| string_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::dump |
( |
const int |
indent = -1, |
|
|
const char |
indent_char = ' ', |
|
|
const bool |
ensure_ascii = false, |
|
|
const error_handler_t |
error_handler = error_handler_t::strict |
|
) |
| const |
|
inline |
serialization
Serialization function for JSON values. The function tries to mimic Python's json.dumps() function, and currently supports its indent and ensure_ascii parameters.
- Parameters
-
| [in] | indent | If indent is nonnegative, then array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. -1 (the default) selects the most compact representation. |
| [in] | indent_char | The character to use for indentation if indent is greater than 0. The default is (space). |
| [in] | ensure_ascii | If ensure_ascii is true, all non-ASCII characters in the output are escaped with \uXXXX sequences, and the result consists of ASCII characters only. |
| [in] | error_handler | how to react on decoding errors; there are three possible values: strict (throws and exception in case a decoding error occurs; default), replace (replace invalid UTF-8 sequences with U+FFFD), and ignore (ignore invalid UTF-8 sequences during serialization). |
- Returns
- string containing the serialization of the JSON value
- Exceptions
-
| type_error.316 | if a string stored inside the JSON value is not UTF-8 encoded |
Linear.
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
{The following example shows the effect of different indent\, indent_char\, and ensure_ascii parameters to the result of the serialization.,dump}
- See Also
- https://docs.python.org/2/library/json.html#json.dump
- Since
- version 1.0.0; indentation character indent_char, option ensure_ascii and exceptions added in version 3.0.0; error handlers added in version 3.4.0.
Definition at line 16560 of file json.hpp.
16566 serializer s(detail::output_adapter<char, string_t>(result), indent_char, error_handler);
16570 s.dump(*
this,
true, ensure_ascii, static_cast<unsigned int>(indent));
16574 s.dump(*
this,
false, ensure_ascii, 0);
::nlohmann::detail::serializer< basic_json > serializer
StringType string_t
a type for a string
then echo File list $list not found else cat $list while read file do echo $file sed s
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class... Args>
| std::pair<iterator, bool> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::emplace |
( |
Args &&... |
args | ) |
|
|
inline |
add an object to an object if key does not exist
Inserts a new element into a JSON object constructed in-place with the given args if there is no element with the key in the container. If the function is called on a JSON null value, an empty object is created before appending the value created from args.
- Parameters
-
| [in] | args | arguments to forward to a constructor of basic_json |
- Template Parameters
-
| Args | compatible types to create a basic_json object |
- Returns
- a pair consisting of an iterator to the inserted element, or the already-existing element if no insertion happened, and a bool denoting whether the insertion took place.
- Exceptions
-
| type_error.311 | when called on a type other than JSON object or null; example: "cannot use emplace() with number" |
Logarithmic in the size of the container, O(log(size())).
{The example shows how emplace() can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object. Further note how no value is added if there was already one value stored with the same key.,emplace}
- Since
- version 2.0.8
Definition at line 19649 of file json.hpp.
19669 it.m_it.object_iterator = res.first;
19672 return {it, res.second};
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
iterator begin() noexcept
returns an iterator to the first element
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class... Args>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::emplace_back |
( |
Args &&... |
args | ) |
|
|
inline |
add an object to an array
Creates a JSON value from the passed parameters args to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending the value created from args.
- Parameters
-
| [in] | args | arguments to forward to a constructor of basic_json |
- Template Parameters
-
| Args | compatible types to create a basic_json object |
- Returns
- reference to the inserted element
- Exceptions
-
| type_error.311 | when called on a type other than JSON array or null; example: "cannot use emplace_back() with number" |
Amortized constant.
{The example shows how push_back() can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,emplace_back}
- Since
- version 2.0.8, returns reference since 3.7.0
Definition at line 19596 of file json.hpp.
19613 #ifdef JSON_HAS_CPP_17
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::empty |
( |
| ) |
const |
|
inlinenoexcept |
checks whether the container is empty.
Checks if a JSON value has no elements (i.e. whether its size is 0).
- Returns
- The return value depends on the different types and is defined as follows:
{The following code uses
empty() to check if a JSON object contains any elements.,empty}
Constant, as long as array_t and object_t satisfy the Container concept; that is, their empty() functions have constant complexity.
No changes.
No-throw guarantee: this function never throws exceptions.
- Note
- This function does not return whether a string stored as JSON value is empty - it returns whether the JSON container itself is empty which is false in the case of a string.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
begin() == end().
- See Also
- size() – returns the number of elements
- Since
- version 1.0.0
Definition at line 19123 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::end |
( |
void |
| ) |
|
|
inlinenoexcept |
returns an iterator to one past the last element
Returns an iterator to one past the last element.
Illustration from cppreference.com
- Returns
- iterator one past the last element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
{The following code shows an example for end().,end}
- See Also
- cend() – returns a const iterator to the end
-
begin() – returns an iterator to the beginning
-
cbegin() – returns a const iterator to the beginning
- Since
- version 1.0.0
Definition at line 18745 of file json.hpp.
iter_impl< basic_json > iterator
an iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::end |
( |
void |
| ) |
const |
|
inlinenoexcept |
returns a const iterator to one past the last element
Returns a const iterator to one past the last element.
Illustration from cppreference.com
- Returns
- const iterator one past the last element
Constant.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).end().
{The following code shows an example for cend().,cend}
- See Also
- end() – returns an iterator to the end
-
begin() – returns an iterator to the beginning
-
cbegin() – returns a const iterator to the beginning
- Since
- version 1.0.0
Definition at line 18755 of file json.hpp.
const_iterator cend() const noexcept
returns a const iterator to one past the last element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value orstd::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
| IteratorType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::erase |
( |
IteratorType |
pos | ) |
|
|
inline |
remove element given an iterator
Removes the element specified by iterator pos. The iterator pos must be valid and dereferenceable. Thus the end() iterator (which is valid, but is not dereferenceable) cannot be used as a value for pos.
If called on a primitive type other than null, the resulting JSON value will be null.
- Parameters
-
| [in] | pos | iterator to the element to remove |
- Returns
- Iterator following the last removed element. If the iterator pos refers to the last element, the
end() iterator is returned.
- Template Parameters
-
- Postcondition
- Invalidates iterators and references at or after the point of the erase, including the
end() iterator.
- Exceptions
-
| type_error.307 | if called on a null value; example: "cannot use
erase() with null" |
| invalid_iterator.202 | if called on an iterator which does not belong to the current JSON value; example: "iterator does not fit current
value" |
| invalid_iterator.205 | if called on a primitive type with invalid iterator (i.e., any iterator which is not begin()); example: "iterator
out of range" |
The complexity depends on the type:
- objects: amortized constant
- arrays: linear in distance between pos and the end of the container
- strings: linear in the length of the string
- other types: constant
{The example shows the result of erase() for different JSON types.,erase__IteratorType}
- See Also
- erase(IteratorType, IteratorType) – removes the elements in the given range
-
erase(const typename object_t::key_type&) – removes the element from an object at the given key
-
erase(const size_type) – removes the element from an array at the given index
- Since
- version 1.0.0
Definition at line 18240 of file json.hpp.
18248 IteratorType result =
end();
18265 AllocatorType<string_t> alloc;
18266 std::allocator_traits<decltype(alloc)>::destroy(alloc,
m_value.
string);
18267 std::allocator_traits<decltype(alloc)>::deallocate(alloc,
m_value.
string, 1);
18278 result.m_it.object_iterator =
m_value.
object->erase(pos.m_it.object_iterator);
18284 result.m_it.array_iterator =
m_value.
array->erase(pos.m_it.array_iterator);
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
string_t * string
string (stored with pointer to save storage)
array (ordered collection of values)
iterator end() noexcept
returns an iterator to one past the last element
number value (signed integer)
#define JSON_THROW(exception)
constexpr bool is_string() const noexcept
return whether value is a string
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
static invalid_iterator create(int id_, const std::string &what_arg)
number value (unsigned integer)
number value (floating-point)
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class IteratorType , typename std::enable_if< std::is_same< IteratorType, typename basic_json_t::iterator >::value orstd::is_same< IteratorType, typename basic_json_t::const_iterator >::value, int >::type = 0>
| IteratorType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::erase |
( |
IteratorType |
first, |
|
|
IteratorType |
last |
|
) |
| |
|
inline |
remove elements given an iterator range
Removes the element specified by the range [first; last). The iterator first does not need to be dereferenceable if first == last: erasing an empty range is a no-op.
If called on a primitive type other than null, the resulting JSON value will be null.
- Parameters
-
| [in] | first | iterator to the beginning of the range to remove |
| [in] | last | iterator past the end of the range to remove |
- Returns
- Iterator following the last removed element. If the iterator second refers to the last element, the
end() iterator is returned.
- Template Parameters
-
- Postcondition
- Invalidates iterators and references at or after the point of the erase, including the
end() iterator.
- Exceptions
-
| type_error.307 | if called on a null value; example: "cannot use
erase() with null" |
| invalid_iterator.203 | if called on iterators which does not belong to the current JSON value; example: "iterators do not fit current value" |
| invalid_iterator.204 | if called on a primitive type with invalid iterators (i.e., if first != begin() and last != end()); example: "iterators out of range" |
The complexity depends on the type:
- objects:
log(size()) + std::distance(first, last)
- arrays: linear in the distance between first and last, plus linear in the distance between last and end of the container
- strings: linear in the length of the string
- other types: constant
{The example shows the result of erase() for different JSON types.,erase__IteratorType_IteratorType}
- See Also
- erase(IteratorType) – removes the element at a given position
-
erase(const typename object_t::key_type&) – removes the element from an object at the given key
-
erase(const size_type) – removes the element from an array at the given index
- Since
- version 1.0.0
Definition at line 18345 of file json.hpp.
18353 IteratorType result =
end();
18364 or not last.m_it.primitive_iterator.is_end()))
18371 AllocatorType<string_t> alloc;
18372 std::allocator_traits<decltype(alloc)>::destroy(alloc,
m_value.
string);
18373 std::allocator_traits<decltype(alloc)>::deallocate(alloc,
m_value.
string, 1);
18385 last.m_it.object_iterator);
18392 last.m_it.array_iterator);
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
string_t * string
string (stored with pointer to save storage)
array (ordered collection of values)
iterator end() noexcept
returns an iterator to one past the last element
number value (signed integer)
#define JSON_THROW(exception)
constexpr bool is_string() const noexcept
return whether value is a string
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
static invalid_iterator create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_LIKELY(expr)
number value (unsigned integer)
number value (floating-point)
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::erase |
( |
const typename object_t::key_type & |
key | ) |
|
|
inline |
remove element from a JSON object given a key
Removes elements from a JSON object with the key value key.
- Parameters
-
| [in] | key | value of the elements to remove |
- Returns
- Number of elements removed. If ObjectType is the default
std::map type, the return value will always be 0 (key was not found) or 1 (key was found).
- Postcondition
- References and iterators to the erased elements are invalidated. Other references and iterators are not affected.
- Exceptions
-
| type_error.307 | when called on a type other than JSON object; example: "cannot use erase() with null" |
log(size()) + count(key)
{The example shows the effect of erase().,erase__key_type}
- See Also
- erase(IteratorType) – removes the element at a given position
-
erase(IteratorType, IteratorType) – removes the elements in the given range
-
erase(const size_type) – removes the element from an array at the given index
- Since
- version 1.0.0
Definition at line 18432 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::erase |
( |
const size_type |
idx | ) |
|
|
inline |
remove element from a JSON array given an index
Removes element from a JSON array at the index idx.
- Parameters
-
| [in] | idx | index of the element to remove |
- Exceptions
-
| type_error.307 | when called on a type other than JSON object; example: "cannot use erase() with null" |
| out_of_range.401 | when idx >= size(); example: "array index 17
is out of range" |
Linear in distance between idx and the end of the container.
{The example shows the effect of erase().,erase__size_type}
- See Also
- erase(IteratorType) – removes the element at a given position
-
erase(IteratorType, IteratorType) – removes the elements in the given range
-
erase(const typename object_t::key_type&) – removes the element from an object at the given key
- Since
- version 1.0.0
Definition at line 18467 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
std::ptrdiff_t difference_type
a type to represent differences between iterators
#define JSON_THROW(exception)
size_type size() const noexcept
returns the number of elements
#define JSON_HEDLEY_LIKELY(expr)
std::string to_string(WindowPattern const &pattern)
constexpr bool is_array() const noexcept
return whether value is an array
static out_of_range create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename KeyT >
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::find |
( |
KeyT && |
key | ) |
|
|
inline |
find an element in a JSON object
Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned.
- Note
- This method always returns end() when executed on a JSON type that is not an object.
- Parameters
-
| [in] | key | key value of the element to search for. |
- Returns
- Iterator to an element with key equivalent to key. If no such element is found or the JSON value is not an object, past-the-end (see end()) iterator is returned.
Logarithmic in the size of the JSON object.
{The example shows how find() is used.,find__key_type}
- See Also
- contains(KeyT&&) const – checks whether a key exists
- Since
- version 1.0.0
Definition at line 18520 of file json.hpp.
18522 auto result =
end();
18526 result.m_it.object_iterator =
m_value.
object->find(std::forward<KeyT>(key));
object_t * object
object (stored with pointer to save storage)
iterator end() noexcept
returns an iterator to one past the last element
constexpr bool is_object() const noexcept
return whether value is an object
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename KeyT >
| const_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::find |
( |
KeyT && |
key | ) |
const |
|
inline |
find an element in a JSON object
find an element in a JSON object Finds an element in a JSON object with key equivalent to key. If the element is not found or the JSON value is not an object, end() is returned.
- Note
- This method always returns end() when executed on a JSON type that is not an object.
- Parameters
-
| [in] | key | key value of the element to search for. |
- Returns
- Iterator to an element with key equivalent to key. If no such element is found or the JSON value is not an object, past-the-end (see end()) iterator is returned.
Logarithmic in the size of the JSON object.
{The example shows how find() is used.,find__key_type}
- See Also
- contains(KeyT&&) const – checks whether a key exists
- Since
- version 1.0.0
Definition at line 18537 of file json.hpp.
18539 auto result =
cend();
18543 result.m_it.object_iterator =
m_value.
object->find(std::forward<KeyT>(key));
object_t * object
object (stored with pointer to save storage)
constexpr bool is_object() const noexcept
return whether value is an object
const_iterator cend() const noexcept
returns a const iterator to one past the last element
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::flatten |
( |
| ) |
const |
|
inline |
return flattened JSON value
The function creates a JSON object whose keys are JSON pointers (see RFC 6901) and whose values are all primitive. The original JSON value can be restored using the unflatten() function.
- Returns
- an object that maps JSON pointers to primitive values
- Note
- Empty objects and arrays are flattened to
null and will not be reconstructed correctly by the unflatten() function.
Linear in the size the JSON value.
{The following code shows how a JSON object is flattened to an object whose keys consist of JSON pointers.,flatten}
- See Also
- unflatten() for the reverse function
- Since
- version 2.0.0
Definition at line 22012 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
object (unordered set of name/value pairs)
static void flatten(const std::string &reference_string, const BasicJsonType &value, BasicJsonType &result)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_bson |
( |
detail::input_adapter && |
i, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
Create a JSON value from an input in BSON format.
Deserializes a given input i to a JSON value using the BSON (Binary JSON) serialization format.
The library maps BSON record types to JSON value types as follows:
| BSON type | BSON marker byte | JSON value type |
| double | 0x01 | number_float |
| string | 0x02 | string |
| document | 0x03 | object |
| array | 0x04 | array |
| binary | 0x05 | still unsupported |
| undefined | 0x06 | still unsupported |
| ObjectId | 0x07 | still unsupported |
| boolean | 0x08 | boolean |
| UTC Date-Time | 0x09 | still unsupported |
| null | 0x0A | null |
| Regular Expr. | 0x0B | still unsupported |
| DB Pointer | 0x0C | still unsupported |
| JavaScript Code | 0x0D | still unsupported |
| Symbol | 0x0E | still unsupported |
| JavaScript Code | 0x0F | still unsupported |
| int32 | 0x10 | number_integer |
| Timestamp | 0x11 | still unsupported |
| 128-bit decimal float | 0x13 | still unsupported |
| Max Key | 0x7F | still unsupported |
| Min Key | 0xFF | still unsupported |
- Warning
- The mapping is incomplete. The unsupported mappings are indicated in the table above.
- Parameters
-
| [in] | i | an input in BSON format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.114 | if an unsupported BSON record type is encountered |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in BSON format to a JSON value.,from_bson}
- See Also
- http://bsonspec.org/spec.html
-
to_bson(const basic_json&) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
Definition at line 21801 of file json.hpp.
21806 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21807 const bool res =
binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::bson, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_bson |
( |
A1 && |
a1, |
|
|
A2 && |
a2, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
Create a JSON value from an input in BSON format.
Deserializes a given input i to a JSON value using the BSON (Binary JSON) serialization format.
The library maps BSON record types to JSON value types as follows:
| BSON type | BSON marker byte | JSON value type |
| double | 0x01 | number_float |
| string | 0x02 | string |
| document | 0x03 | object |
| array | 0x04 | array |
| binary | 0x05 | still unsupported |
| undefined | 0x06 | still unsupported |
| ObjectId | 0x07 | still unsupported |
| boolean | 0x08 | boolean |
| UTC Date-Time | 0x09 | still unsupported |
| null | 0x0A | null |
| Regular Expr. | 0x0B | still unsupported |
| DB Pointer | 0x0C | still unsupported |
| JavaScript Code | 0x0D | still unsupported |
| Symbol | 0x0E | still unsupported |
| JavaScript Code | 0x0F | still unsupported |
| int32 | 0x10 | number_integer |
| Timestamp | 0x11 | still unsupported |
| 128-bit decimal float | 0x13 | still unsupported |
| Max Key | 0x7F | still unsupported |
| Min Key | 0xFF | still unsupported |
- Warning
- The mapping is incomplete. The unsupported mappings are indicated in the table above.
- Parameters
-
| [in] | i | an input in BSON format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.114 | if an unsupported BSON record type is encountered |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in BSON format to a JSON value.,from_bson}
- See Also
- http://bsonspec.org/spec.html
-
to_bson(const basic_json&) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
Definition at line 21817 of file json.hpp.
21822 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21823 const bool res =
binary_reader(detail::input_adapter(std::forward<A1>(
a1), std::forward<A2>(
a2))).sax_parse(input_format_t::bson, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_cbor |
( |
detail::input_adapter && |
i, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in CBOR format
Deserializes a given input i to a JSON value using the CBOR (Concise Binary Object Representation) serialization format.
The library maps CBOR types to JSON value types as follows:
| CBOR type | JSON value type | first byte |
| Integer | number_unsigned | 0x00..0x17 |
| Unsigned integer | number_unsigned | 0x18 |
| Unsigned integer | number_unsigned | 0x19 |
| Unsigned integer | number_unsigned | 0x1A |
| Unsigned integer | number_unsigned | 0x1B |
| Negative integer | number_integer | 0x20..0x37 |
| Negative integer | number_integer | 0x38 |
| Negative integer | number_integer | 0x39 |
| Negative integer | number_integer | 0x3A |
| Negative integer | number_integer | 0x3B |
| Negative integer | number_integer | 0x40..0x57 |
| UTF-8 string | string | 0x60..0x77 |
| UTF-8 string | string | 0x78 |
| UTF-8 string | string | 0x79 |
| UTF-8 string | string | 0x7A |
| UTF-8 string | string | 0x7B |
| UTF-8 string | string | 0x7F |
| array | array | 0x80..0x97 |
| array | array | 0x98 |
| array | array | 0x99 |
| array | array | 0x9A |
| array | array | 0x9B |
| array | array | 0x9F |
| map | object | 0xA0..0xB7 |
| map | object | 0xB8 |
| map | object | 0xB9 |
| map | object | 0xBA |
| map | object | 0xBB |
| map | object | 0xBF |
| False | false | 0xF4 |
| True | true | 0xF5 |
| Null | null | 0xF6 |
| Half-Precision Float | number_float | 0xF9 |
| Single-Precision Float | number_float | 0xFA |
| Double-Precision Float | number_float | 0xFB |
- Warning
- The mapping is incomplete in the sense that not all CBOR types can be converted to a JSON value. The following CBOR types are not supported and will yield parse errors (parse_error.112):
- byte strings (0x40..0x5F)
- date/time (0xC0..0xC1)
- bignum (0xC2..0xC3)
- decimal fraction (0xC4)
- bigfloat (0xC5)
- tagged items (0xC6..0xD4, 0xD8..0xDB)
- expected conversions (0xD5..0xD7)
- simple values (0xE0..0xF3, 0xF8)
- undefined (0xF7)
-
CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected (parse_error.113).
- Note
- Any CBOR output created to_cbor can be successfully parsed by from_cbor.
- Parameters
-
| [in] | i | an input in CBOR format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if unsupported features from CBOR were used in the given input v or if the input is not valid CBOR |
| parse_error.113 | if a string was expected as map key, but not found |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in CBOR format to a JSON value.,from_cbor}
- See Also
- http://cbor.io
-
to_cbor(const basic_json&) for the analogous serialization
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
- Since
- version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0
Definition at line 21517 of file json.hpp.
21522 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21523 const bool res =
binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::cbor, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_cbor |
( |
A1 && |
a1, |
|
|
A2 && |
a2, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in CBOR format
Deserializes a given input i to a JSON value using the CBOR (Concise Binary Object Representation) serialization format.
The library maps CBOR types to JSON value types as follows:
| CBOR type | JSON value type | first byte |
| Integer | number_unsigned | 0x00..0x17 |
| Unsigned integer | number_unsigned | 0x18 |
| Unsigned integer | number_unsigned | 0x19 |
| Unsigned integer | number_unsigned | 0x1A |
| Unsigned integer | number_unsigned | 0x1B |
| Negative integer | number_integer | 0x20..0x37 |
| Negative integer | number_integer | 0x38 |
| Negative integer | number_integer | 0x39 |
| Negative integer | number_integer | 0x3A |
| Negative integer | number_integer | 0x3B |
| Negative integer | number_integer | 0x40..0x57 |
| UTF-8 string | string | 0x60..0x77 |
| UTF-8 string | string | 0x78 |
| UTF-8 string | string | 0x79 |
| UTF-8 string | string | 0x7A |
| UTF-8 string | string | 0x7B |
| UTF-8 string | string | 0x7F |
| array | array | 0x80..0x97 |
| array | array | 0x98 |
| array | array | 0x99 |
| array | array | 0x9A |
| array | array | 0x9B |
| array | array | 0x9F |
| map | object | 0xA0..0xB7 |
| map | object | 0xB8 |
| map | object | 0xB9 |
| map | object | 0xBA |
| map | object | 0xBB |
| map | object | 0xBF |
| False | false | 0xF4 |
| True | true | 0xF5 |
| Null | null | 0xF6 |
| Half-Precision Float | number_float | 0xF9 |
| Single-Precision Float | number_float | 0xFA |
| Double-Precision Float | number_float | 0xFB |
- Warning
- The mapping is incomplete in the sense that not all CBOR types can be converted to a JSON value. The following CBOR types are not supported and will yield parse errors (parse_error.112):
- byte strings (0x40..0x5F)
- date/time (0xC0..0xC1)
- bignum (0xC2..0xC3)
- decimal fraction (0xC4)
- bigfloat (0xC5)
- tagged items (0xC6..0xD4, 0xD8..0xDB)
- expected conversions (0xD5..0xD7)
- simple values (0xE0..0xF3, 0xF8)
- undefined (0xF7)
-
CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected (parse_error.113).
- Note
- Any CBOR output created to_cbor can be successfully parsed by from_cbor.
- Parameters
-
| [in] | i | an input in CBOR format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if unsupported features from CBOR were used in the given input v or if the input is not valid CBOR |
| parse_error.113 | if a string was expected as map key, but not found |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in CBOR format to a JSON value.,from_cbor}
- See Also
- http://cbor.io
-
to_cbor(const basic_json&) for the analogous serialization
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
- Since
- version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0
Definition at line 21533 of file json.hpp.
21538 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21539 const bool res =
binary_reader(detail::input_adapter(std::forward<A1>(
a1), std::forward<A2>(
a2))).sax_parse(input_format_t::cbor, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_msgpack |
( |
detail::input_adapter && |
i, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in MessagePack format
Deserializes a given input i to a JSON value using the MessagePack serialization format.
The library maps MessagePack types to JSON value types as follows:
| MessagePack type | JSON value type | first byte |
| positive fixint | number_unsigned | 0x00..0x7F |
| fixmap | object | 0x80..0x8F |
| fixarray | array | 0x90..0x9F |
| fixstr | string | 0xA0..0xBF |
| nil | null | 0xC0 |
| false | false | 0xC2 |
| true | true | 0xC3 |
| float 32 | number_float | 0xCA |
| float 64 | number_float | 0xCB |
| uint 8 | number_unsigned | 0xCC |
| uint 16 | number_unsigned | 0xCD |
| uint 32 | number_unsigned | 0xCE |
| uint 64 | number_unsigned | 0xCF |
| int 8 | number_integer | 0xD0 |
| int 16 | number_integer | 0xD1 |
| int 32 | number_integer | 0xD2 |
| int 64 | number_integer | 0xD3 |
| str 8 | string | 0xD9 |
| str 16 | string | 0xDA |
| str 32 | string | 0xDB |
| array 16 | array | 0xDC |
| array 32 | array | 0xDD |
| map 16 | object | 0xDE |
| map 32 | object | 0xDF |
| negative fixint | number_integer | 0xE0-0xFF |
- Warning
- The mapping is incomplete in the sense that not all MessagePack types can be converted to a JSON value. The following MessagePack types are not supported and will yield parse errors:
- bin 8 - bin 32 (0xC4..0xC6)
- ext 8 - ext 32 (0xC7..0xC9)
- fixext 1 - fixext 16 (0xD4..0xD8)
- Note
- Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.
- Parameters
-
| [in] | i | an input in MessagePack format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if unsupported features from MessagePack were used in the given input i or if the input is not valid MessagePack |
| parse_error.113 | if a string was expected as map key, but not found |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in MessagePack format to a JSON value.,from_msgpack}
- See Also
- http://msgpack.org
-
to_msgpack(const basic_json&) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
-
from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format
- Since
- version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0
Definition at line 21626 of file json.hpp.
21631 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21632 const bool res =
binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::msgpack, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_msgpack |
( |
A1 && |
a1, |
|
|
A2 && |
a2, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in MessagePack format
Deserializes a given input i to a JSON value using the MessagePack serialization format.
The library maps MessagePack types to JSON value types as follows:
| MessagePack type | JSON value type | first byte |
| positive fixint | number_unsigned | 0x00..0x7F |
| fixmap | object | 0x80..0x8F |
| fixarray | array | 0x90..0x9F |
| fixstr | string | 0xA0..0xBF |
| nil | null | 0xC0 |
| false | false | 0xC2 |
| true | true | 0xC3 |
| float 32 | number_float | 0xCA |
| float 64 | number_float | 0xCB |
| uint 8 | number_unsigned | 0xCC |
| uint 16 | number_unsigned | 0xCD |
| uint 32 | number_unsigned | 0xCE |
| uint 64 | number_unsigned | 0xCF |
| int 8 | number_integer | 0xD0 |
| int 16 | number_integer | 0xD1 |
| int 32 | number_integer | 0xD2 |
| int 64 | number_integer | 0xD3 |
| str 8 | string | 0xD9 |
| str 16 | string | 0xDA |
| str 32 | string | 0xDB |
| array 16 | array | 0xDC |
| array 32 | array | 0xDD |
| map 16 | object | 0xDE |
| map 32 | object | 0xDF |
| negative fixint | number_integer | 0xE0-0xFF |
- Warning
- The mapping is incomplete in the sense that not all MessagePack types can be converted to a JSON value. The following MessagePack types are not supported and will yield parse errors:
- bin 8 - bin 32 (0xC4..0xC6)
- ext 8 - ext 32 (0xC7..0xC9)
- fixext 1 - fixext 16 (0xD4..0xD8)
- Note
- Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.
- Parameters
-
| [in] | i | an input in MessagePack format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if unsupported features from MessagePack were used in the given input i or if the input is not valid MessagePack |
| parse_error.113 | if a string was expected as map key, but not found |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in MessagePack format to a JSON value.,from_msgpack}
- See Also
- http://msgpack.org
-
to_msgpack(const basic_json&) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the related UBJSON format
-
from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format
- Since
- version 2.0.9; parameter start_index since 2.1.1; changed to consume input adapters, removed start_index parameter, and added strict parameter since 3.0.0; added allow_exceptions parameter since 3.2.0
Definition at line 21642 of file json.hpp.
21647 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21648 const bool res =
binary_reader(detail::input_adapter(std::forward<A1>(
a1), std::forward<A2>(
a2))).sax_parse(input_format_t::msgpack, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_ubjson |
( |
detail::input_adapter && |
i, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in UBJSON format
Deserializes a given input i to a JSON value using the UBJSON (Universal Binary JSON) serialization format.
The library maps UBJSON types to JSON value types as follows:
| UBJSON type | JSON value type | marker |
| no-op | no value, next value is read | N |
| null | null | Z |
| false | false | F |
| true | true | T |
| float32 | number_float | d |
| float64 | number_float | D |
| uint8 | number_unsigned | U |
| int8 | number_integer | i |
| int16 | number_integer | I |
| int32 | number_integer | l |
| int64 | number_integer | L |
| string | string | S |
| char | string | C |
| array | array (optimized values are supported) | [ |
| object | object (optimized values are supported) | { |
- Note
- The mapping is complete in the sense that any UBJSON value can be converted to a JSON value.
- Parameters
-
| [in] | i | an input in UBJSON format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if a parse error occurs |
| parse_error.113 | if a string could not be parsed successfully |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in UBJSON format to a JSON value.,from_ubjson}
- See Also
- http://ubjson.org
-
to_ubjson(const basic_json&, const bool, const bool) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format
- Since
- version 3.1.0; added allow_exceptions parameter since 3.2.0
Definition at line 21714 of file json.hpp.
21719 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21720 const bool res =
binary_reader(detail::input_adapter(i)).sax_parse(input_format_t::ubjson, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename A1 , typename A2 , detail::enable_if_t< std::is_constructible< detail::input_adapter, A1, A2 >::value, int > = 0>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::from_ubjson |
( |
A1 && |
a1, |
|
|
A2 && |
a2, |
|
|
const bool |
strict = true, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
create a JSON value from an input in UBJSON format
Deserializes a given input i to a JSON value using the UBJSON (Universal Binary JSON) serialization format.
The library maps UBJSON types to JSON value types as follows:
| UBJSON type | JSON value type | marker |
| no-op | no value, next value is read | N |
| null | null | Z |
| false | false | F |
| true | true | T |
| float32 | number_float | d |
| float64 | number_float | D |
| uint8 | number_unsigned | U |
| int8 | number_integer | i |
| int16 | number_integer | I |
| int32 | number_integer | l |
| int64 | number_integer | L |
| string | string | S |
| char | string | C |
| array | array (optimized values are supported) | [ |
| object | object (optimized values are supported) | { |
- Note
- The mapping is complete in the sense that any UBJSON value can be converted to a JSON value.
- Parameters
-
| [in] | i | an input in UBJSON format convertible to an input adapter |
| [in] | strict | whether to expect the input to be consumed until EOF (true by default) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.110 | if the given input ends prematurely or the end of file was not reached when strict was set to true |
| parse_error.112 | if a parse error occurs |
| parse_error.113 | if a string could not be parsed successfully |
Linear in the size of the input i.
{The example shows the deserialization of a byte vector in UBJSON format to a JSON value.,from_ubjson}
- See Also
- http://ubjson.org
-
to_ubjson(const basic_json&, const bool, const bool) for the analogous serialization
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the related CBOR format
-
from_msgpack(detail::input_adapter&&, const bool, const bool) for the related MessagePack format
-
from_bson(detail::input_adapter&&, const bool, const bool) for the related BSON format
- Since
- version 3.1.0; added allow_exceptions parameter since 3.2.0
Definition at line 21730 of file json.hpp.
21735 detail::json_sax_dom_parser<basic_json> sdp(result, allow_exceptions);
21736 const bool res =
binary_reader(detail::input_adapter(std::forward<A1>(
a1), std::forward<A2>(
a2))).sax_parse(input_format_t::ubjson, &sdp, strict);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::binary_reader< basic_json > binary_reader
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::front |
( |
| ) |
|
|
inline |
access the first element
Returns a reference to the first element in the container. For a JSON container c, the expression c.front() is equivalent to *c.begin().
- Returns
- In case of a structured type (array or object), a reference to the first element is returned. In case of number, string, or boolean values, a reference to the value is returned.
Constant.
- Precondition
- The JSON value must not be
null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).
- Postcondition
- The JSON value remains unchanged.
- Exceptions
-
| invalid_iterator.214 | when called on null value |
{The following code shows an example for front().,front}
- See Also
- back() – access the last element
- Since
- version 1.0.0
Definition at line 18129 of file json.hpp.
iterator begin() noexcept
returns an iterator to the first element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::front |
( |
| ) |
const |
|
inline |
access the first element
Returns a reference to the first element in the container. For a JSON container c, the expression c.front() is equivalent to *c.begin().
- Returns
- In case of a structured type (array or object), a reference to the first element is returned. In case of number, string, or boolean values, a reference to the value is returned.
Constant.
- Precondition
- The JSON value must not be
null (would throw std::out_of_range) or an empty array or object (undefined behavior, guarded by assertions).
- Postcondition
- The JSON value remains unchanged.
- Exceptions
-
| invalid_iterator.214 | when called on null value |
{The following code shows an example for front().,front}
- See Also
- back() – access the last element
- Since
- version 1.0.0
Definition at line 18137 of file json.hpp.
const_iterator cbegin() const noexcept
returns a const iterator to the first element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType , detail::enable_if_t< std::is_same< typename std::remove_const< BasicJsonType >::type, basic_json_t >::value, int > = 0>
| basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
const |
|
inline |
get special-case overload
This overloads avoids a lot of template boilerplate, it can be seen as the identity method
- Template Parameters
-
- Returns
- a copy of *this
Constant.
- Since
- version 2.1.0
Definition at line 17101 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType , detail::enable_if_t< not std::is_same< BasicJsonType, basic_json >::value anddetail::is_basic_json< BasicJsonType >::value, int > = 0>
| BasicJsonType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
const |
|
inline |
get special-case overload
This overloads converts the current basic_json in a different basic_json type
- Template Parameters
-
- Returns
- a copy of *this, converted into
- Template Parameters
-
| BasicJsonType | Depending on the implementation of the called from_json() method. |
- Since
- version 3.2.0
Definition at line 17124 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< not detail::is_basic_json< ValueType >::value anddetail::has_from_json< basic_json_t, ValueType >::value andnot detail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>
| ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
const |
|
inlinenoexcept |
get a value (explicit)
Explicit type conversion between the JSON value and a compatible value which is CopyConstructible and DefaultConstructible. The value is converted by calling the json_serializer<ValueType> from_json() method.
The function is equivalent to executing
This overloads is chosen if:
- Template Parameters
-
| ValueTypeCV | the provided value type |
| ValueType | the returned value type |
- Returns
- copy of the JSON value, converted to ValueType
- Exceptions
-
{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,get__ValueType_const}
- Since
- version 2.1.0
Definition at line 17174 of file json.hpp.
17181 "get() cannot be used with reference types, you might want to use get_ref()");
17183 "types must be DefaultConstructible when used with get()");
void from_json(const BasicJsonType &j, typename std::nullptr_t &n)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ValueTypeCV , typename ValueType = detail::uncvref_t<ValueTypeCV>, detail::enable_if_t< not std::is_same< basic_json_t, ValueType >::value anddetail::has_non_default_from_json< basic_json_t, ValueType >::value, int > = 0>
| ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
const |
|
inlinenoexcept |
get a value (explicit); special case
Explicit type conversion between the JSON value and a compatible value which is not CopyConstructible and not DefaultConstructible. The value is converted by calling the json_serializer<ValueType> from_json() method.
The function is equivalent to executing
This overloads is chosen if:
- Note
- If json_serializer<ValueType> has both overloads of
from_json(), this one is chosen.
- Template Parameters
-
| ValueTypeCV | the provided value type |
| ValueType | the returned value type |
- Returns
- copy of the JSON value, converted to ValueType
- Exceptions
-
- Since
- version 2.1.0
Definition at line 17225 of file json.hpp.
17229 "get() cannot be used with reference types, you might want to use get_ref()");
void from_json(const BasicJsonType &j, typename std::nullptr_t &n)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
| auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
-> decltype(std::declval<basic_json_t&>().template get_ptr<PointerType>())
|
|
inlinenoexcept |
get a pointer value (explicit)
Explicit pointer access to the internally stored JSON value. No copies are made.
- Warning
- The pointer becomes invalid if the underlying JSON object changes.
- Template Parameters
-
- Returns
- pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value;
nullptr otherwise
Constant.
{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get__PointerType}
- See Also
- get_ptr() for explicit pointer-member access
- Since
- version 1.0.0
Definition at line 17368 of file json.hpp.
17371 return get_ptr<PointerType>();
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
| constexpr auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get |
( |
| ) |
const -> decltype(std::declval<const basic_json_t&>().template get_ptr<PointerType>())
|
|
inlinenoexcept |
get a pointer value (explicit)
get a pointer value (explicit) Explicit pointer access to the internally stored JSON value. No copies are made.
- Warning
- The pointer becomes invalid if the underlying JSON object changes.
- Template Parameters
-
- Returns
- pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value;
nullptr otherwise
Constant.
{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get__PointerType}
- See Also
- get_ptr() for explicit pointer-member access
- Since
- version 1.0.0
Definition at line 17380 of file json.hpp.
17383 return get_ptr<PointerType>();
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>
| auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_ptr |
( |
| ) |
-> decltype(std::declval<basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
|
|
inlinenoexcept |
get a pointer value (implicit)
Implicit pointer access to the internally stored JSON value. No copies are made.
- Warning
- Writing data to the pointee of the result yields an undefined state.
- Template Parameters
-
- Returns
- pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value;
nullptr otherwise
Constant.
{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get_ptr}
- Since
- version 1.0.0
Definition at line 17320 of file json.hpp.
17323 return get_impl_ptr(static_cast<PointerType>(
nullptr));
object_t * get_impl_ptr(object_t *) noexcept
get a pointer to the value (object)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value andstd::is_const< typename std::remove_pointer< PointerType >::type >::value, int >::type = 0>
| constexpr auto nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_ptr |
( |
| ) |
const -> decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
|
|
inlinenoexcept |
get a pointer value (implicit)
get a pointer value (implicit) Implicit pointer access to the internally stored JSON value. No copies are made.
- Warning
- Writing data to the pointee of the result yields an undefined state.
- Template Parameters
-
- Returns
- pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value;
nullptr otherwise
Constant.
{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get_ptr}
- Since
- version 1.0.0
Definition at line 17333 of file json.hpp.
17336 return get_impl_ptr(static_cast<PointerType>(
nullptr));
object_t * get_impl_ptr(object_t *) noexcept
get a pointer to the value (object)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value, int >::type = 0>
| ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_ref |
( |
| ) |
|
|
inline |
get a reference value (implicit)
Implicit reference access to the internally stored JSON value. No copies are made.
- Warning
- Writing data to the referee of the result yields an undefined state.
- Template Parameters
-
- Returns
- reference to the internally stored JSON value if the requested reference type ReferenceType fits to the JSON value; throws type_error.303 otherwise
- Exceptions
-
| type_error.303 | in case passed type ReferenceType is incompatible with the stored JSON value; see example below |
Constant.
{The example shows several calls to get_ref().,get_ref}
- Since
- version 1.1.0
Definition at line 17414 of file json.hpp.
17417 return get_ref_impl<ReferenceType>(*this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ReferenceType , typename std::enable_if< std::is_reference< ReferenceType >::value andstd::is_const< typename std::remove_reference< ReferenceType >::type >::value, int >::type = 0>
| ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_ref |
( |
| ) |
const |
|
inline |
get a reference value (implicit)
get a reference value (implicit) Implicit reference access to the internally stored JSON value. No copies are made.
- Warning
- Writing data to the referee of the result yields an undefined state.
- Template Parameters
-
- Returns
- reference to the internally stored JSON value if the requested reference type ReferenceType fits to the JSON value; throws type_error.303 otherwise
- Exceptions
-
| type_error.303 | in case passed type ReferenceType is incompatible with the stored JSON value; see example below |
Constant.
{The example shows several calls to get_ref().,get_ref}
- Since
- version 1.1.0
Definition at line 17427 of file json.hpp.
17430 return get_ref_impl<ReferenceType>(*this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ReferenceType , typename ThisType >
| static ReferenceType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_ref_impl |
( |
ThisType & |
obj | ) |
|
|
inlinestaticprivate |
helper function to implement get_ref()
This function helps to implement get_ref() without code duplication for const and non-const overloads
- Template Parameters
-
- Exceptions
-
| type_error.303 | if ReferenceType does not match underlying value type of the current JSON |
Definition at line 17066 of file json.hpp.
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ValueType , detail::enable_if_t< not detail::is_basic_json< ValueType >::value anddetail::has_from_json< basic_json_t, ValueType >::value, int > = 0>
| ValueType& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_to |
( |
ValueType & |
v | ) |
const |
|
inlinenoexcept |
get a value (explicit)
Explicit type conversion between the JSON value and a compatible value. The value is filled into the input parameter by calling the json_serializer<ValueType> from_json() method.
The function is equivalent to executing
This overloads is chosen if:
- Template Parameters
-
| ValueType | the input parameter type. |
- Returns
- the input parameter, allowing chaining calls.
- Exceptions
-
{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,get_to}
- Since
- version 3.3.0
Definition at line 17271 of file json.hpp.
void from_json(const BasicJsonType &j, typename std::nullptr_t &n)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename T , std::size_t N, typename Array = T (&)[N], detail::enable_if_t< detail::has_from_json< basic_json_t, Array >::value, int > = 0>
| Array nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::get_to |
( |
T(&) |
v[N] | ) |
const |
|
inlinenoexcept |
Definition at line 17283 of file json.hpp.
void from_json(const BasicJsonType &j, typename std::nullptr_t &n)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::insert |
( |
const_iterator |
pos, |
|
|
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
val |
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) |
| |
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inline |
inserts element
Inserts element val before iterator pos.
- Parameters
-
| [in] | pos | iterator before which the content will be inserted; may be the end() iterator |
| [in] | val | element to insert |
- Returns
- iterator pointing to the inserted val.
- Exceptions
-
| type_error.309 | if called on JSON values other than arrays; example: "cannot use insert() with string" |
| invalid_iterator.202 | if pos is not an iterator of *this; example: "iterator does not fit current value" |
Constant plus linear in the distance between pos and end of the container.
{The example shows how insert() is used.,insert}
- Since
- version 1.0.0
Definition at line 19717 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
#define JSON_THROW(exception)
iterator insert_iterator(const_iterator pos, Args &&...args)
static invalid_iterator create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_LIKELY(expr)
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::insert |
( |
const_iterator |
pos, |
|
|
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > && |
val |
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) |
| |
|
inline |
inserts element
inserts element Inserts element val before iterator pos.
- Parameters
-
| [in] | pos | iterator before which the content will be inserted; may be the end() iterator |
| [in] | val | element to insert |
- Returns
- iterator pointing to the inserted val.
- Exceptions
-
| type_error.309 | if called on JSON values other than arrays; example: "cannot use insert() with string" |
| invalid_iterator.202 | if pos is not an iterator of *this; example: "iterator does not fit current value" |
Constant plus linear in the distance between pos and end of the container.
{The example shows how insert() is used.,insert}
- Since
- version 1.0.0
Definition at line 19739 of file json.hpp.
19741 return insert(pos, val);
iterator insert(const_iterator pos, const basic_json &val)
inserts element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::insert |
( |
const_iterator |
pos, |
|
|
size_type |
cnt, |
|
|
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
val |
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) |
| |
|
inline |
inserts elements
Inserts cnt copies of val before iterator pos.
- Parameters
-
| [in] | pos | iterator before which the content will be inserted; may be the end() iterator |
| [in] | cnt | number of copies of val to insert |
| [in] | val | element to insert |
- Returns
- iterator pointing to the first element inserted, or pos if
cnt==0
- Exceptions
-
| type_error.309 | if called on JSON values other than arrays; example: "cannot use insert() with string" |
| invalid_iterator.202 | if pos is not an iterator of *this; example: "iterator does not fit current value" |
Linear in cnt plus linear in the distance between pos and end of the container.
{The example shows how insert() is used.,insert__count}
- Since
- version 1.0.0
Definition at line 19768 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
#define JSON_THROW(exception)
iterator insert_iterator(const_iterator pos, Args &&...args)
static invalid_iterator create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_LIKELY(expr)
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::insert |
( |
const_iterator |
pos, |
|
|
const_iterator |
first, |
|
|
const_iterator |
last |
|
) |
| |
|
inline |
inserts elements
Inserts elements from range [first, last) before iterator pos.
- Parameters
-
| [in] | pos | iterator before which the content will be inserted; may be the end() iterator |
| [in] | first | begin of the range of elements to insert |
| [in] | last | end of the range of elements to insert |
- Exceptions
-
| type_error.309 | if called on JSON values other than arrays; example: "cannot use insert() with string" |
| invalid_iterator.202 | if pos is not an iterator of *this; example: "iterator does not fit current value" |
| invalid_iterator.210 | if first and last do not belong to the same JSON value; example: "iterators do not fit" |
| invalid_iterator.211 | if first or last are iterators into container for which insert is called; example: "passed iterators may not
belong to container" |
- Returns
- iterator pointing to the first element inserted, or pos if
first==last
Linear in std::distance(first, last) plus linear in the distance between pos and end of the container.
{The example shows how insert() is used.,insert__range}
- Since
- version 1.0.0
Definition at line 19816 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
#define JSON_THROW(exception)
iterator insert_iterator(const_iterator pos, Args &&...args)
static invalid_iterator create(int id_, const std::string &what_arg)
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
inserts elements
Inserts elements from initializer list ilist before iterator pos.
- Parameters
-
| [in] | pos | iterator before which the content will be inserted; may be the end() iterator |
| [in] | ilist | initializer list to insert the values from |
- Exceptions
-
| type_error.309 | if called on JSON values other than arrays; example: "cannot use insert() with string" |
| invalid_iterator.202 | if pos is not an iterator of *this; example: "iterator does not fit current value" |
- Returns
- iterator pointing to the first element inserted, or pos if
ilist is empty
Linear in ilist.size() plus linear in the distance between pos and end of the container.
{The example shows how insert() is used.,insert__ilist}
- Since
- version 1.0.0
Definition at line 19869 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
#define JSON_THROW(exception)
iterator insert_iterator(const_iterator pos, Args &&...args)
static invalid_iterator create(int id_, const std::string &what_arg)
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
inserts elements
Inserts elements from range [first, last).
- Parameters
-
| [in] | first | begin of the range of elements to insert |
| [in] | last | end of the range of elements to insert |
- Exceptions
-
| type_error.309 | if called on JSON values other than objects; example: "cannot use insert() with string" |
| invalid_iterator.202 | if iterator first or last does does not point to an object; example: "iterators first and last must point to
objects" |
| invalid_iterator.210 | if first and last do not belong to the same JSON value; example: "iterators do not fit" |
Logarithmic: O(N*log(size() + N)), where N is the number of elements to insert.
{The example shows how insert() is used.,insert__range_object}
- Since
- version 3.0.0
Definition at line 19910 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
static invalid_iterator create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_array |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is an array
This function returns true if and only if the JSON value is an array.
- Returns
true if type is array, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_array() for all JSON types.,is_array}
- Since
- version 1.0.0
Definition at line 16872 of file json.hpp.
array (ordered collection of values)
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_boolean |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is a boolean
This function returns true if and only if the JSON value is a boolean.
- Returns
true if type is boolean, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_boolean() for all JSON types.,is_boolean}
- Since
- version 1.0.0
Definition at line 16713 of file json.hpp.
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_discarded |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is discarded
This function returns true if and only if the JSON value was discarded during parsing with a callback function (see parser_callback_t).
- Note
- This function will always be
false for JSON values after parsing. That is, discarded values can only occur during parsing, but will be removed when inside a structured value or replaced by null in other cases.
- Returns
true if type is discarded, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_discarded() for all JSON types.,is_discarded}
- Since
- version 1.0.0
Definition at line 16921 of file json.hpp.
value_t m_type
the type of the current element
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_null |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is null
This function returns true if and only if the JSON value is null.
- Returns
true if type is null, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_null() for all JSON types.,is_null}
- Since
- version 1.0.0
Definition at line 16691 of file json.hpp.
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_number |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is a number
This function returns true if and only if the JSON value is a number. This includes both integer (signed and unsigned) and floating-point values.
- Returns
true if type is number (regardless whether integer, unsigned integer or floating-type), false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_number() for all JSON types.,is_number}
- See Also
- is_number_integer() – check if value is an integer or unsigned integer number
-
is_number_unsigned() – check if value is an unsigned integer number
-
is_number_float() – check if value is a floating-point number
- Since
- version 1.0.0
Definition at line 16743 of file json.hpp.
constexpr bool is_number_float() const noexcept
return whether value is a floating-point number
constexpr bool is_number_integer() const noexcept
return whether value is an integer number
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_number_float |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is a floating-point number
This function returns true if and only if the JSON value is a floating-point number. This excludes signed and unsigned integer values.
- Returns
true if type is a floating-point number, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_number_float() for all JSON types.,is_number_float}
- See Also
- is_number() – check if value is number
-
is_number_integer() – check if value is an integer number
-
is_number_unsigned() – check if value is an unsigned integer number
- Since
- version 1.0.0
Definition at line 16828 of file json.hpp.
value_t m_type
the type of the current element
number value (floating-point)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_number_integer |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is an integer number
This function returns true if and only if the JSON value is a signed or unsigned integer number. This excludes floating-point values.
- Returns
true if type is an integer or unsigned integer number, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_number_integer() for all JSON types.,is_number_integer}
- See Also
- is_number() – check if value is a number
-
is_number_unsigned() – check if value is an unsigned integer number
-
is_number_float() – check if value is a floating-point number
- Since
- version 1.0.0
Definition at line 16772 of file json.hpp.
number value (signed integer)
value_t m_type
the type of the current element
number value (unsigned integer)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_number_unsigned |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is an unsigned integer number
This function returns true if and only if the JSON value is an unsigned integer number. This excludes floating-point and signed integer values.
- Returns
true if type is an unsigned integer number, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_number_unsigned() for all JSON types.,is_number_unsigned}
- See Also
- is_number() – check if value is a number
-
is_number_integer() – check if value is an integer or unsigned integer number
-
is_number_float() – check if value is a floating-point number
- Since
- version 2.0.0
Definition at line 16800 of file json.hpp.
value_t m_type
the type of the current element
number value (unsigned integer)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_object |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is an object
This function returns true if and only if the JSON value is an object.
- Returns
true if type is object, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_object() for all JSON types.,is_object}
- Since
- version 1.0.0
Definition at line 16850 of file json.hpp.
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_primitive |
( |
| ) |
const |
|
inlinenoexcept |
return whether type is primitive
This function returns true if and only if the JSON type is primitive (string, number, boolean, or null).
- Returns
true if type is primitive (string, number, boolean, or null), false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_primitive() for all JSON types.,is_primitive}
- See Also
- is_structured() – returns whether JSON value is structured
-
is_null() – returns whether JSON value is
null
-
is_string() – returns whether JSON value is a string
-
is_boolean() – returns whether JSON value is a boolean
-
is_number() – returns whether JSON value is a number
- Since
- version 1.0.0
Definition at line 16642 of file json.hpp.
constexpr bool is_null() const noexcept
return whether value is null
constexpr bool is_number() const noexcept
return whether value is a number
constexpr bool is_boolean() const noexcept
return whether value is a boolean
constexpr bool is_string() const noexcept
return whether value is a string
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_string |
( |
| ) |
const |
|
inlinenoexcept |
return whether value is a string
This function returns true if and only if the JSON value is a string.
- Returns
true if type is string, false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_string() for all JSON types.,is_string}
- Since
- version 1.0.0
Definition at line 16894 of file json.hpp.
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::is_structured |
( |
| ) |
const |
|
inlinenoexcept |
return whether type is structured
This function returns true if and only if the JSON type is structured (array or object).
- Returns
true if type is structured (array or object), false otherwise.
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies is_structured() for all JSON types.,is_structured}
- See Also
- is_primitive() – returns whether value is primitive
-
is_array() – returns whether value is an array
-
is_object() – returns whether value is an object
- Since
- version 1.0.0
Definition at line 16669 of file json.hpp.
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_array() const noexcept
return whether value is an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
helper to access iterator member functions in range-based for
This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.
For loop without items() function:
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
Range-based for loop without items() function:
for (auto it : j_object)
{
}
Range-based for loop with items() function:
for (auto& el : j_object.items())
{
std::cout <<
"key: " << el.key() <<
", value:" << el.value() <<
'\n';
}
The items() function also allows to use structured bindings (C++17):
for (auto& [key, val] : j_object.items())
{
std::cout <<
"key: " << key <<
", value:" << val <<
'\n';
}
- Note
- When iterating over an array,
key() will return the index of the element as string (see example). For primitive types (e.g., numbers), key() returns an empty string.
- Returns
- iteration proxy object wrapping ref with an interface to use in range-based for loops
{The following code shows how the function is used.,items}
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 3.1.0, structured bindings support since 3.5.0.
Definition at line 19059 of file json.hpp.
19061 return iteration_proxy<iterator>(*this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
helper to access iterator member functions in range-based for
This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.
For loop without items() function:
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
Range-based for loop without items() function:
for (auto it : j_object)
{
}
Range-based for loop with items() function:
for (auto& el : j_object.items())
{
std::cout <<
"key: " << el.key() <<
", value:" << el.value() <<
'\n';
}
The items() function also allows to use structured bindings (C++17):
for (auto& [key, val] : j_object.items())
{
std::cout <<
"key: " << key <<
", value:" << val <<
'\n';
}
- Note
- When iterating over an array,
key() will return the index of the element as string (see example). For primitive types (e.g., numbers), key() returns an empty string.
- Returns
- iteration proxy object wrapping ref with an interface to use in range-based for loops
{The following code shows how the function is used.,items}
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Since
- version 3.1.0, structured bindings support since 3.5.0.
Definition at line 19067 of file json.hpp.
19069 return iteration_proxy<const_iterator>(*this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
wrapper to access iterator member functions in range-based for
This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.
For loop without iterator_wrapper:
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
Range-based for loop without iterator proxy:
for (auto it : j_object)
{
}
Range-based for loop with iterator proxy:
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
- Note
- When iterating over an array,
key() will return the index of the element as string (see example).
- Parameters
-
| [in] | ref | reference to a JSON value |
- Returns
- iteration proxy object wrapping ref with an interface to use in range-based for loops
{The following code shows how the wrapper is used,iterator_wrapper}
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Note
- The name of this function is not yet final and may change in the future.
- Deprecated:
- This stream operator is deprecated and will be removed in future 4.0.0 of the library. Please use items() instead; that is, replace
json::iterator_wrapper(j) with j.items().
Definition at line 18982 of file json.hpp.
18984 return ref.items();
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
wrapper to access iterator member functions in range-based for
This function allows to access iterator::key() and iterator::value() during range-based for loops. In these loops, a reference to the JSON values is returned, so there is no access to the underlying iterator.
For loop without iterator_wrapper:
for (auto it = j_object.begin(); it != j_object.end(); ++it)
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
Range-based for loop without iterator proxy:
for (auto it : j_object)
{
}
Range-based for loop with iterator proxy:
{
std::cout <<
"key: " << it.key() <<
", value:" << it.value() <<
'\n';
}
- Note
- When iterating over an array,
key() will return the index of the element as string (see example).
- Parameters
-
| [in] | ref | reference to a JSON value |
- Returns
- iteration proxy object wrapping ref with an interface to use in range-based for loops
{The following code shows how the wrapper is used,iterator_wrapper}
Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
Constant.
- Note
- The name of this function is not yet final and may change in the future.
- Deprecated:
- This stream operator is deprecated and will be removed in future 4.0.0 of the library. Please use items() instead; that is, replace
json::iterator_wrapper(j) with j.items().
Definition at line 18991 of file json.hpp.
18993 return ref.items();
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::max_size |
( |
| ) |
const |
|
inlinenoexcept |
returns the maximum possible number of elements
Returns the maximum number of elements a JSON value is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the JSON value.
- Returns
- The return value depends on the different types and is defined as follows:
| Value type | return value |
| null | 0 (same as size()) |
| boolean | 1 (same as size()) |
| string | 1 (same as size()) |
| number | 1 (same as size()) |
| object | result of function object_t::max_size() |
| array | result of function array_t::max_size() |
{The following code calls max_size() on the different value types. Note the output is implementation specific.,max_size}
Constant, as long as array_t and object_t satisfy the Container concept; that is, their max_size() functions have constant complexity.
No changes.
No-throw guarantee: this function never throws exceptions.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of returning
b.size() where b is the largest possible JSON value.
- See Also
- size() – returns the number of elements
- Since
- version 1.0.0
Definition at line 19265 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
size_type size() const noexcept
returns the number of elements
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::merge_patch |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
apply_patch | ) |
|
|
inline |
applies a JSON Merge Patch
The merge patch format is primarily intended for use with the HTTP PATCH method as a means of describing a set of modifications to a target resource's content. This function applies a merge patch to the current JSON value.
The function implements the following algorithm from Section 2 of RFC 7396 (JSON Merge Patch):
``` define MergePatch(Target, Patch): if Patch is an Object: if Target is not an Object: Target = {} // Ignore the contents and set it to an empty Object for each Name/Value pair in Patch: if Value is null: if Name exists in Target: remove the Name/Value pair from Target else: Target[Name] = MergePatch(Target[Name], Value) return Target else: return Patch ```
Thereby, Target is the current object; that is, the patch is applied to the current value.
- Parameters
-
| [in] | apply_patch | the patch to apply |
Linear in the lengths of patch.
{The following code shows how a JSON Merge Patch is applied to a JSON document.,merge_patch}
- See Also
- patch – apply a JSON patch
-
RFC 7396 (JSON Merge Patch)
- Since
- version 3.0.0
Definition at line 22581 of file json.hpp.
22583 if (apply_patch.is_object())
22589 for (
auto it = apply_patch.begin(); it != apply_patch.end(); ++it)
22591 if (it.value().is_null())
22603 *
this = apply_patch;
IteratorType erase(IteratorType pos)
remove element given an iterator
void merge_patch(const basic_json &apply_patch)
applies a JSON Merge Patch
constexpr bool is_object() const noexcept
return whether value is an object
static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json object(initializer_list_t init={})
explicitly create an object from an initializer list
reference operator[](size_type idx)
access specified array element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
returns version information on the library
This function returns a JSON object with information about the library, including the version number and information on the platform and compiler.
- Returns
- JSON object holding version information
| key | description |
compiler | Information on the used compiler. It is an object with the following keys: c++ (the used C++ standard), family (the compiler family; possible values are clang, icc, gcc, ilecpp, msvc, pgcpp, sunpro, and unknown), and version (the compiler version). |
copyright | The copyright line for the library as string. |
name | The name of the library as string. |
platform | The used platform as string. Possible values are win32, linux, apple, unix, and unknown. |
url | The URL of the project as string. |
version | The version of the library. It is an object with the following keys: major, minor, and patch as defined by Semantic Versioning, and string (the version string). |
{The following code shows an example output of the meta() function.,meta}
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
Constant.
- Since
- 2.1.0
Definition at line 14866 of file json.hpp.
14870 result[
"copyright"] =
"(C) 2013-2017 Niels Lohmann";
14871 result[
"name"] =
"JSON for Modern C++";
14872 result[
"url"] =
"https://github.com/nlohmann/json";
14873 result[
"version"][
"string"] =
14882 result[
"platform"] =
"win32";
14883 #elif defined __linux__
14884 result[
"platform"] =
"linux";
14885 #elif defined __APPLE__
14886 result[
"platform"] =
"apple";
14887 #elif defined __unix__
14888 result[
"platform"] =
"unix";
14890 result[
"platform"] =
"unknown";
14893 #if defined(__ICC) || defined(__INTEL_COMPILER)
14894 result[
"compiler"] = {{
"family",
"icc"}, {
"version", __INTEL_COMPILER}};
14895 #elif defined(__clang__)
14896 result[
"compiler"] = {{
"family",
"clang"}, {
"version", __clang_version__}};
14897 #elif defined(__GNUC__) || defined(__GNUG__)
14899 #elif defined(__HP_cc) || defined(__HP_aCC)
14900 result[
"compiler"] =
"hp"
14901 #elif defined(__IBMCPP__)
14902 result[
"compiler"] = {{
"family",
"ilecpp"}, {
"version", __IBMCPP__}};
14903 #elif defined(_MSC_VER)
14904 result[
"compiler"] = {{
"family",
"msvc"}, {
"version", _MSC_VER}};
14905 #elif defined(__PGI)
14906 result[
"compiler"] = {{
"family",
"pgcpp"}, {
"version", __PGI}};
14907 #elif defined(__SUNPRO_CC)
14908 result[
"compiler"] = {{
"family",
"sunpro"}, {
"version", __SUNPRO_CC}};
14910 result[
"compiler"] = {{
"family",
"unknown"}, {
"version",
"unknown"}};
14916 result[
"compiler"][
"c++"] =
"unknown";
basic_json(const value_t v)
create an empty value with a given type
#define NLOHMANN_JSON_VERSION_PATCH
#define NLOHMANN_JSON_VERSION_MINOR
std::string to_string(WindowPattern const &pattern)
#define NLOHMANN_JSON_VERSION_MAJOR
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
explicitly create an object from an initializer list
Creates a JSON object value from a given initializer list. The initializer lists elements must be pairs, and their first elements must be strings. If the initializer list is empty, the empty object {} is created.
- Note
- This function is only added for symmetry reasons. In contrast to the related function array(initializer_list_t), there are no cases which can only be expressed by this function. That is, any initializer list init can also be passed to the initializer list constructor basic_json(initializer_list_t, bool, value_t).
- Parameters
-
| [in] | init | initializer list to create an object from (optional) |
- Returns
- JSON object value
- Exceptions
-
| type_error.301 | if init is not a list of pairs whose first elements are strings. In this case, no object can be created. When such a value is passed to basic_json(initializer_list_t, bool, value_t), an array would have been created from the passed initializer list init. See example below. |
Linear in the size of init.
Strong guarantee: if an exception is thrown, there are no changes to any JSON value.
{The following code shows an example for the object function.,object}
- See Also
- basic_json(initializer_list_t, bool, value_t) – create a JSON value from an initializer list
-
array(initializer_list_t) – create a JSON array value from an initializer list
- Since
- version 1.0.0
Definition at line 16133 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
object (unordered set of name/value pairs)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator value_t |
( |
| ) |
const |
|
inlinenoexcept |
return the type of the JSON value (implicit)
Implicitly return the type of the JSON value as a value from the value_t enumeration.
- Returns
- the type of the JSON value
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies the value_t operator for all JSON types.,operator__value_t}
- See Also
- type() – return the type of the JSON value (explicit)
-
type_name() – return the type as string
- Since
- version 1.0.0
Definition at line 16947 of file json.hpp.
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ValueType , typename std::enable_if< not std::is_pointer< ValueType >::value andnot std::is_same< ValueType, detail::json_ref< basic_json >>::value andnot std::is_same< ValueType, typename string_t::value_type >::value andnot detail::is_basic_json< ValueType >::valueand not std::is_same< ValueType, std::initializer_list< typename string_t::value_type >>::valueand not std::is_same< ValueType, typename std::string_view >::valueand detail::is_detected< detail::get_template_function, const basic_json_t &, ValueType >::value, int >::type = 0>
| nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator ValueType |
( |
| ) |
const |
|
inline |
get a value (implicit)
Implicit type conversion between the JSON value and a compatible value. The call is realized by calling get() const.
- Template Parameters
-
| ValueType | non-pointer type compatible to the JSON value, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. The character type of string_t as well as an initializer list of this type is excluded to avoid ambiguities as these types implicitly convert to std::string. |
- Returns
- copy of the JSON value, converted to type ValueType
- Exceptions
-
| type_error.302 | in case passed type ValueType is incompatible to the JSON value type (e.g., the JSON value is of type boolean, but a string is requested); see example below |
Linear in the size of the JSON value.
{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,operator__ValueType}
- Since
- version 1.0.0
Definition at line 17476 of file json.hpp.
17479 return get<ValueType>();
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator+= |
( |
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > && |
val | ) |
|
|
inline |
add an object to an array
add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.
- Parameters
-
| [in] | val | the value to add to the JSON array |
- Exceptions
-
| type_error.308 | when called on a type other than JSON array or null; example: "cannot use push_back() with number" |
Amortized constant.
{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}
- Since
- version 1.0.0
Definition at line 19433 of file json.hpp.
void push_back(basic_json &&val)
add an object to an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator+= |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
val | ) |
|
|
inline |
add an object to an array
add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.
- Parameters
-
| [in] | val | the value to add to the JSON array |
- Exceptions
-
| type_error.308 | when called on a type other than JSON array or null; example: "cannot use push_back() with number" |
Amortized constant.
{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}
- Since
- version 1.0.0
Definition at line 19467 of file json.hpp.
void push_back(basic_json &&val)
add an object to an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator+= |
( |
const typename object_t::value_type & |
val | ) |
|
|
inline |
add an object to an object
add an object to an object Inserts the given element val to the JSON object. If the function is called on a JSON null value, an empty object is created before inserting val.
- Parameters
-
| [in] | val | the value to add to the JSON object |
- Exceptions
-
| type_error.308 | when called on a type other than JSON object or null; example: "cannot use push_back() with number" |
Logarithmic in the size of the container, O(log(size())).
{The example shows how push_back() and += can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object.,push_back__object_t__value}
- Since
- version 1.0.0
Definition at line 19517 of file json.hpp.
void push_back(basic_json &&val)
add an object to an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
add an object to an object
add an object to an object This function allows to use push_back with an initializer list. In case
- the current value is an object,
- the initializer list init contains only two elements, and
- the first element of init is a string,
init is converted into an object element and added using push_back(const typename object_t::value_type&). Otherwise, init is converted to a JSON value and added using push_back(basic_json&&).
- Parameters
-
| [in] | init | an initializer list |
Linear in the size of the initializer list init.
- Note
- This function is required to resolve an ambiguous overload error, because pairs like
{"key", "value"} can be both interpreted as object_t::value_type or std::initializer_list<basic_json>, see https://github.com/nlohmann/json/issues/235 for more information.
{The example shows how initializer lists are treated as objects when possible.,push_back__initializer_list}
Definition at line 19566 of file json.hpp.
void push_back(basic_json &&val)
add an object to an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| basic_json& nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator= |
( |
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > |
other | ) |
|
|
inlinenoexcept |
copy assignment
Copy assignment operator. Copies a JSON value via the "copy and swap" strategy: It is expressed in terms of the copy constructor, destructor, and the swap() member function.
- Parameters
-
| [in] | other | value to copy from |
Linear.
This function helps basic_json satisfying the Container requirements:
- The complexity is linear.
{The code below shows and example for the copy assignment. It creates a copy of value a which is then swapped with b. Finally\, the copy of a (which is the null value after the swap) is destroyed.,basic_json__copyassignment}
- Since
- version 1.0.0
Definition at line 16469 of file json.hpp.
16477 other.assert_invariant();
void swap(reference other) noexcept(std::is_nothrow_move_constructible< value_t >::value andstd::is_nothrow_move_assignable< value_t >::value andstd::is_nothrow_move_constructible< json_value >::value andstd::is_nothrow_move_assignable< json_value >::value)
exchanges the values
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
size_type |
idx | ) |
|
|
inline |
access specified array element
Returns a reference to the element at specified location idx.
- Note
- If idx is beyond the range of the array (i.e.,
idx >= size()), then the array is silently filled up with null values to make idx a valid reference to the last stored element.
- Parameters
-
| [in] | idx | index of the element to access |
- Returns
- reference to the element at index idx
- Exceptions
-
| type_error.305 | if the JSON value is not an array or null; in that cases, using the [] operator with an index makes no sense. |
Constant if idx is in the range of the array. Otherwise linear in idx - size().
{The example below shows how array elements can be read and written using [] operator. Note the addition of null values.,operatorarray__size_type}
- Since
- version 1.0.0
Definition at line 17714 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
basic_json(const value_t v)
create an empty value with a given type
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_LIKELY(expr)
constexpr bool is_array() const noexcept
return whether value is an array
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified array element
Returns a const reference to the element at specified location idx.
- Parameters
-
| [in] | idx | index of the element to access |
- Returns
- const reference to the element at index idx
- Exceptions
-
| type_error.305 | if the JSON value is not an array; in that case, using the [] operator with an index makes no sense. |
Constant.
{The example below shows how array elements can be read using the [] operator.,operatorarray__size_type_const}
- Since
- version 1.0.0
Definition at line 17760 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
constexpr bool is_array() const noexcept
return whether value is an array
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
const typename object_t::key_type & |
key | ) |
|
|
inline |
access specified object element
Returns a reference to the element at with specified key key.
- Note
- If key is not found in the object, then it is silently added to the object and filled with a
null value to make key a valid reference. In case the value was null before, it is converted to an object.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- reference to the element at key key
- Exceptions
-
| type_error.305 | if the JSON value is not an object or null; in that cases, using the [] operator with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be read and written using the [] operator.,operatorarray__key_type}
- See Also
- at(const typename object_t::key_type&) for access by reference with range checking
-
value() for access by value with a default value
- Since
- version 1.0.0
Definition at line 17798 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
const typename object_t::key_type & |
key | ) |
const |
|
inline |
read-only access specified object element
Returns a const reference to the element at with specified key key. No bounds checking is performed.
- Warning
- If the element with key key does not exist, the behavior is undefined.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- const reference to the element at key key
- Precondition
- The element with key key must exist. This precondition is enforced with an assertion.
- Exceptions
-
| type_error.305 | if the JSON value is not an object; in that case, using the [] operator with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be read using the [] operator.,operatorarray__key_type_const}
- See Also
- at(const typename object_t::key_type&) for access by reference with range checking
-
value() for access by value with a default value
- Since
- version 1.0.0
Definition at line 17847 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename T >
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
T * |
key | ) |
|
|
inline |
access specified object element
Returns a reference to the element at with specified key key.
- Note
- If key is not found in the object, then it is silently added to the object and filled with a
null value to make key a valid reference. In case the value was null before, it is converted to an object.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- reference to the element at key key
- Exceptions
-
| type_error.305 | if the JSON value is not an object or null; in that cases, using the [] operator with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be read and written using the [] operator.,operatorarray__key_type}
- See Also
- at(const typename object_t::key_type&) for access by reference with range checking
-
value() for access by value with a default value
- Since
- version 1.1.0
Definition at line 17888 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename T >
| const_reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
T * |
key | ) |
const |
|
inline |
read-only access specified object element
Returns a const reference to the element at with specified key key. No bounds checking is performed.
- Warning
- If the element with key key does not exist, the behavior is undefined.
- Parameters
-
| [in] | key | key of the element to access |
- Returns
- const reference to the element at key key
- Precondition
- The element with key key must exist. This precondition is enforced with an assertion.
- Exceptions
-
| type_error.305 | if the JSON value is not an object; in that case, using the [] operator with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be read using the [] operator.,operatorarray__key_type_const}
- See Also
- at(const typename object_t::key_type&) for access by reference with range checking
-
value() for access by value with a default value
- Since
- version 1.1.0
Definition at line 17939 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reference nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::operator[] |
( |
const json_pointer & |
ptr | ) |
|
|
inline |
access specified element via JSON Pointer
Uses a JSON pointer to retrieve a reference to the respective JSON value. No bound checking is performed. Similar to operator[](const typename object_t::key_type&), null values are created in arrays and objects if necessary.
In particular:
- If the JSON pointer points to an object key that does not exist, it is created an filled with a
null value before a reference to it is returned.
- If the JSON pointer points to an array index that does not exist, it is created an filled with a
null value before a reference to it is returned. All indices between the current maximum and the given index are also filled with null.
- The special value
- is treated as a synonym for the index past the end.
- Parameters
-
- Returns
- reference to the element pointed to by ptr
Constant.
- Exceptions
-
| parse_error.106 | if an array index begins with '0' |
| parse_error.109 | if an array index was not a number |
| out_of_range.404 | if the JSON pointer can not be resolved |
{The behavior is shown in the example.,operatorjson_pointer}
- Since
- version 2.0.0
Definition at line 21871 of file json.hpp.
21873 return ptr.get_unchecked(
this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
access specified element via JSON Pointer
Uses a JSON pointer to retrieve a reference to the respective JSON value. No bound checking is performed. The function does not change the JSON value; no null values are created. In particular, the the special value - yields an exception.
- Parameters
-
| [in] | ptr | JSON pointer to the desired element |
- Returns
- const reference to the element pointed to by ptr
Constant.
- Exceptions
-
| parse_error.106 | if an array index begins with '0' |
| parse_error.109 | if an array index was not a number |
| out_of_range.402 | if the array index '-' is used |
| out_of_range.404 | if the JSON pointer can not be resolved |
{The behavior is shown in the example.,operatorjson_pointer_const}
- Since
- version 2.0.0
Definition at line 21899 of file json.hpp.
21901 return ptr.get_unchecked(
this);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static JSON_HEDLEY_WARN_UNUSED_RESULT basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::parse |
( |
detail::input_adapter && |
i, |
|
|
const parser_callback_t |
cb = nullptr, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
deserialize from a compatible input
This function reads from a compatible input. Examples are:
- an array of 1-byte values
- strings with character/literal type with size of 1 byte
- input streams
- container with contiguous storage of 1-byte values. Compatible container types include
std::vector, std::string, std::array, std::valarray, and std::initializer_list. Furthermore, C-style arrays can be used with std::begin()/std::end(). User-defined containers can be used as long as they implement random-access iterators and a contiguous storage.
- Precondition
- Each element of the container has a size of 1 byte. Violating this precondition yields undefined behavior. This precondition is enforced with a static assertion.
-
The container storage is contiguous. Violating this precondition yields undefined behavior. This precondition is enforced with an assertion.
- Warning
- There is no way to enforce all preconditions at compile-time. If the function is called with a noncompliant container and with assertions switched off, the behavior is undefined and will most likely yield segmentation violation.
- Parameters
-
| [in] | i | input to read from |
| [in] | cb | a parser callback function of type parser_callback_t which is used to control the deserialization by filtering unwanted values (optional) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.101 | if a parse error occurs; example: ""unexpected end of input; expected string literal"" |
| parse_error.102 | if to_unicode fails or surrogate error |
| parse_error.103 | if to_unicode fails |
Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the parser callback function cb has a super-linear complexity.
- Note
- A UTF-8 byte order mark is silently ignored.
{The example below demonstrates the parse() function reading from an array.,parse__array__parser_callback_t}
{The example below demonstrates the parse() function with and without callback function.,parse__string__parser_callback_t}
{The example below demonstrates the parse() function with and without callback function.,parse__istream__parser_callback_t}
{The example below demonstrates the parse() function reading from a contiguous container.,parse__contiguouscontainer__parser_callback_t}
- Since
- version 2.0.3 (contiguous containers)
Definition at line 20745 of file json.hpp.
20750 parser(i, cb, allow_exceptions).parse(
true, result);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class IteratorType , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0>
| static basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::parse |
( |
IteratorType |
first, |
|
|
IteratorType |
last, |
|
|
const parser_callback_t |
cb = nullptr, |
|
|
const bool |
allow_exceptions = true |
|
) |
| |
|
inlinestatic |
deserialize from an iterator range with contiguous storage
This function reads from an iterator range of a container with contiguous storage of 1-byte values. Compatible container types include std::vector, std::string, std::array, std::valarray, and std::initializer_list. Furthermore, C-style arrays can be used with std::begin()/std::end(). User-defined containers can be used as long as they implement random-access iterators and a contiguous storage.
- Precondition
- The iterator range is contiguous. Violating this precondition yields undefined behavior. This precondition is enforced with an assertion.
-
Each element in the range has a size of 1 byte. Violating this precondition yields undefined behavior. This precondition is enforced with a static assertion.
- Warning
- There is no way to enforce all preconditions at compile-time. If the function is called with noncompliant iterators and with assertions switched off, the behavior is undefined and will most likely yield segmentation violation.
- Template Parameters
-
| IteratorType | iterator of container with contiguous storage |
- Parameters
-
| [in] | first | begin of the range to parse (included) |
| [in] | last | end of the range to parse (excluded) |
| [in] | cb | a parser callback function of type parser_callback_t which is used to control the deserialization by filtering unwanted values (optional) |
| [in] | allow_exceptions | whether to throw exceptions in case of a parse error (optional, true by default) |
- Returns
- deserialized JSON value; in case of a parse error and allow_exceptions set to
false, the return value will be value_t::discarded.
- Exceptions
-
| parse_error.101 | in case of an unexpected token |
| parse_error.102 | if to_unicode fails or surrogate error |
| parse_error.103 | if to_unicode fails |
Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the parser callback function cb has a super-linear complexity.
- Note
- A UTF-8 byte order mark is silently ignored.
{The example below demonstrates the parse() function reading from an iterator range.,parse__iteratortype__parser_callback_t}
- Since
- version 2.0.3
Definition at line 20877 of file json.hpp.
20882 parser(detail::input_adapter(
first, last), cb, allow_exceptions).parse(
true, result);
basic_json(const value_t v)
create an empty value with a given type
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::patch |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
json_patch | ) |
const |
|
inline |
applies a JSON patch
JSON Patch defines a JSON document structure for expressing a sequence of operations to apply to a JSON) document. With this function, a JSON Patch is applied to the current JSON value by executing all operations from the patch.
- Parameters
-
| [in] | json_patch | JSON patch document |
- Returns
- patched document
- Note
- The application of a patch is atomic: Either all operations succeed and the patched document is returned or an exception is thrown. In any case, the original value is not changed: the patch is applied to a copy of the value.
- Exceptions
-
| parse_error.104 | if the JSON patch does not consist of an array of objects |
| parse_error.105 | if the JSON patch is malformed (e.g., mandatory attributes are missing); example: "operation add must have member path" |
| out_of_range.401 | if an array index is out of range. |
| out_of_range.403 | if a JSON pointer inside the patch could not be resolved successfully in the current JSON value; example: "key baz not
found" |
| out_of_range.405 | if JSON pointer has no parent ("add", "remove", "move") |
| other_error.501 | if "test" operation was unsuccessful |
Linear in the size of the JSON value and the length of the JSON patch. As usually only a fraction of the JSON value is affected by the patch, the complexity can usually be neglected.
{The following code shows how a JSON patch is applied to a value.,patch}
- See Also
- diff – create a JSON patch by comparing two JSON values
-
RFC 6902 (JSON Patch)
-
RFC 6901 (JSON Pointer)
- Since
- version 2.0.0
Definition at line 22110 of file json.hpp.
22116 enum class patch_operations {add,
remove,
replace, move,
copy,
test, invalid};
22118 const auto get_op = [](
const std::string & op)
22122 return patch_operations::add;
22124 if (op ==
"remove")
22128 if (op ==
"replace")
22130 return patch_operations::replace;
22134 return patch_operations::move;
22145 return patch_operations::invalid;
22160 if (top_pointer != ptr)
22162 result.at(top_pointer);
22166 const auto last_path = ptr.back();
22170 switch (parent.m_type)
22176 parent[last_path] = val;
22182 if (last_path ==
"-")
22185 parent.push_back(val);
22197 parent.insert(parent.begin() +
static_cast<difference_type>(idx), val);
22209 const auto operation_remove = [&result](
json_pointer & ptr)
22212 const auto last_path = ptr.back();
22217 if (parent.is_object())
22220 auto it = parent.find(last_path);
22230 else if (parent.is_array())
22244 for (
const auto& val : json_patch)
22247 const auto get_value = [&val](
const std::string & op,
22248 const std::string & member,
22252 auto it = val.m_value.object->find(member);
22255 const auto error_msg = (op ==
"op") ?
"operation" :
"operation '" + op +
"'";
22280 const std::string op = get_value(
"op",
"op",
true);
22281 const std::string
path = get_value(op,
"path",
true);
22284 switch (get_op(op))
22286 case patch_operations::add:
22288 operation_add(ptr, get_value(
"add",
"value",
false));
22294 operation_remove(ptr);
22298 case patch_operations::replace:
22301 result.at(ptr) = get_value(
"replace",
"value",
false);
22305 case patch_operations::move:
22307 const std::string from_path = get_value(
"move",
"from",
true);
22317 operation_remove(from_ptr);
22318 operation_add(ptr, v);
22324 const std::string from_path = get_value(
"copy",
"from",
true);
22333 operation_add(ptr, v);
22339 bool success =
false;
22344 success = (result.at(ptr) == get_value(
"test",
"value",
false));
array (ordered collection of values)
static other_error create(int id_, const std::string &what_arg)
basic_json(const value_t v)
create an empty value with a given type
#define JSON_INTERNAL_CATCH(exception)
std::ptrdiff_t difference_type
a type to represent differences between iterators
BEGIN_PROLOG triggeremu_data_config_icarus settings PMTADCthresholds sequence::icarus_stage0_multiTPC_TPC physics sequence::icarus_stage0_EastHits_TPC physics sequence::icarus_stage0_WestHits_TPC physics producers purityana0 caloskimCalorimetryCryoE physics caloskimCalorimetryCryoW physics path
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
::nlohmann::json_pointer< basic_json > json_pointer
JSON Pointer, see nlohmann::json_pointer.
static int array_index(const std::string &s)
#define JSON_HEDLEY_LIKELY(expr)
detail::out_of_range out_of_range
exception indicating access out of the defined range
std::string to_string(WindowPattern const &pattern)
replace invalid UTF-8 sequences with U+FFFD
static out_of_range create(int id_, const std::string &what_arg)
BEGIN_PROLOG hitmakerfive clustermakerfour pfparticlemakerthree showermakertwo END_PROLOG hitmakerfive clustermakerfour pfparticlemakerthree sequence::inline_paths sequence::inline_paths sequence::inline_paths showermakers test
#define JSON_HEDLEY_UNLIKELY(expr)
static parse_error create(int id_, const position_t &pos, const std::string &what_arg)
create a parse error exception
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::push_back |
( |
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > && |
val | ) |
|
|
inline |
add an object to an array
Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.
- Parameters
-
| [in] | val | the value to add to the JSON array |
- Exceptions
-
| type_error.308 | when called on a type other than JSON array or null; example: "cannot use push_back() with number" |
Amortized constant.
{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}
- Since
- version 1.0.0
Definition at line 19406 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::push_back |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
val | ) |
|
|
inline |
add an object to an array
add an object to an array Appends the given element val to the end of the JSON value. If the function is called on a JSON null value, an empty array is created before appending val.
- Parameters
-
| [in] | val | the value to add to the JSON array |
- Exceptions
-
| type_error.308 | when called on a type other than JSON array or null; example: "cannot use push_back() with number" |
Amortized constant.
{The example shows how push_back() and += can be used to add elements to a JSON array. Note how the null value was silently converted to a JSON array.,push_back}
- Since
- version 1.0.0
Definition at line 19443 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
constexpr bool is_array() const noexcept
return whether value is an array
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::push_back |
( |
const typename object_t::value_type & |
val | ) |
|
|
inline |
add an object to an object
Inserts the given element val to the JSON object. If the function is called on a JSON null value, an empty object is created before inserting val.
- Parameters
-
| [in] | val | the value to add to the JSON object |
- Exceptions
-
| type_error.308 | when called on a type other than JSON object or null; example: "cannot use push_back() with number" |
Logarithmic in the size of the container, O(log(size())).
{The example shows how push_back() and += can be used to add elements to a JSON object. Note how the null value was silently converted to a JSON object.,push_back__object_t__value}
- Since
- version 1.0.0
Definition at line 19493 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::push_back |
( |
initializer_list_t |
init | ) |
|
|
inline |
add an object to an object
This function allows to use push_back with an initializer list. In case
- the current value is an object,
- the initializer list init contains only two elements, and
- the first element of init is a string,
init is converted into an object element and added using push_back(const typename object_t::value_type&). Otherwise, init is converted to a JSON value and added using push_back(basic_json&&).
- Parameters
-
| [in] | init | an initializer list |
Linear in the size of the initializer list init.
- Note
- This function is required to resolve an ambiguous overload error, because pairs like
{"key", "value"} can be both interpreted as object_t::value_type or std::initializer_list<basic_json>, see https://github.com/nlohmann/json/issues/235 for more information.
{The example shows how initializer lists are treated as objects when possible.,push_back__initializer_list}
Definition at line 19548 of file json.hpp.
19552 basic_json&& key = init.begin()->moved_or_copied();
19553 push_back(
typename object_t::value_type(
19554 std::move(key.get_ref<
string_t&>()), (init.begin() + 1)->moved_or_copied()));
basic_json(const value_t v)
create an empty value with a given type
StringType string_t
a type for a string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_string() const noexcept
return whether value is a string
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
void push_back(basic_json &&val)
add an object to an array
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::rbegin |
( |
| ) |
|
|
inlinenoexcept |
returns an iterator to the reverse-beginning
Returns an iterator to the reverse-beginning; that is, the last element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
reverse_iterator(end()).
{The following code shows an example for rbegin().,rbegin}
- See Also
- crbegin() – returns a const reverse iterator to the beginning
-
rend() – returns a reverse iterator to the end
-
crend() – returns a const reverse iterator to the end
- Since
- version 1.0.0
Definition at line 18815 of file json.hpp.
iterator end() noexcept
returns an iterator to one past the last element
json_reverse_iterator< typename basic_json::iterator > reverse_iterator
a reverse iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
returns a const reverse iterator to the last element
Returns a const iterator to the reverse-beginning; that is, the last element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).rbegin().
{The following code shows an example for crbegin().,crbegin}
- See Also
- rbegin() – returns a reverse iterator to the beginning
-
rend() – returns a reverse iterator to the end
-
crend() – returns a const reverse iterator to the end
- Since
- version 1.0.0
Definition at line 18823 of file json.hpp.
const_reverse_iterator crbegin() const noexcept
returns a const reverse iterator to the last element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| reverse_iterator nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::rend |
( |
| ) |
|
|
inlinenoexcept |
returns an iterator to the reverse-end
Returns an iterator to the reverse-end; that is, one before the first element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
reverse_iterator(begin()).
{The following code shows an example for rend().,rend}
- See Also
- crend() – returns a const reverse iterator to the end
-
rbegin() – returns a reverse iterator to the beginning
-
crbegin() – returns a const reverse iterator to the beginning
- Since
- version 1.0.0
Definition at line 18852 of file json.hpp.
iterator begin() noexcept
returns an iterator to the first element
json_reverse_iterator< typename basic_json::iterator > reverse_iterator
a reverse iterator for a basic_json container
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
returns a const reverse iterator to one before the first
Returns a const reverse iterator to the reverse-end; that is, one before the first element.
Illustration from cppreference.com
Constant.
This function helps basic_json satisfying the ReversibleContainer requirements:
- The complexity is constant.
- Has the semantics of
const_cast<const basic_json&>(*this).rend().
{The following code shows an example for crend().,crend}
- See Also
- rend() – returns a reverse iterator to the end
-
rbegin() – returns a reverse iterator to the beginning
-
crbegin() – returns a const reverse iterator to the beginning
- Since
- version 1.0.0
Definition at line 18860 of file json.hpp.
const_reverse_iterator crend() const noexcept
returns a const reverse iterator to one before the first
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename SAX >
| static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::sax_parse |
( |
detail::input_adapter && |
i, |
|
|
SAX * |
sax, |
|
|
input_format_t |
format = input_format_t::json, |
|
|
const bool |
strict = true |
|
) |
| |
|
inlinestatic |
generate SAX events
The SAX event lister must follow the interface of json_sax.
This function reads from a compatible input. Examples are:
- an array of 1-byte values
- strings with character/literal type with size of 1 byte
- input streams
- container with contiguous storage of 1-byte values. Compatible container types include
std::vector, std::string, std::array, std::valarray, and std::initializer_list. Furthermore, C-style arrays can be used with std::begin()/std::end(). User-defined containers can be used as long as they implement random-access iterators and a contiguous storage.
- Precondition
- Each element of the container has a size of 1 byte. Violating this precondition yields undefined behavior. This precondition is enforced with a static assertion.
-
The container storage is contiguous. Violating this precondition yields undefined behavior. This precondition is enforced with an assertion.
- Warning
- There is no way to enforce all preconditions at compile-time. If the function is called with a noncompliant container and with assertions switched off, the behavior is undefined and will most likely yield segmentation violation.
- Parameters
-
| [in] | i | input to read from |
| [in,out] | sax | SAX event listener |
| [in] | format | the format to parse (JSON, CBOR, MessagePack, or UBJSON) |
| [in] | strict | whether the input has to be consumed completely |
- Returns
- return value of the last processed SAX event
- Exceptions
-
| parse_error.101 | if a parse error occurs; example: ""unexpected end of input; expected string literal"" |
| parse_error.102 | if to_unicode fails or surrogate error |
| parse_error.103 | if to_unicode fails |
Linear in the length of the input. The parser is a predictive LL(1) parser. The complexity can be higher if the SAX consumer sax has a super-linear complexity.
- Note
- A UTF-8 byte order mark is silently ignored.
{The example below demonstrates the sax_parse() function reading from string and processing the events with a user-defined SAX event consumer.,sax_parse}
- Since
- version 3.2.0
Definition at line 20814 of file json.hpp.
20820 ?
parser(std::move(i)).sax_parse(sax, strict)
20821 : detail::binary_reader<basic_json, SAX>(std::move(i)).
sax_parse(
format, sax, strict);
static std::string format(PyObject *obj, unsigned int pos, unsigned int indent, unsigned int maxlen, unsigned int depth)
static bool sax_parse(detail::input_adapter &&i, SAX *sax, input_format_t format=input_format_t::json, const bool strict=true)
generate SAX events
basic_json<> json
default JSON class
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class IteratorType , class SAX , typename std::enable_if< std::is_base_of< std::random_access_iterator_tag, typename std::iterator_traits< IteratorType >::iterator_category >::value, int >::type = 0>
| static bool nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::sax_parse |
( |
IteratorType |
first, |
|
|
IteratorType |
last, |
|
|
SAX * |
sax |
|
) |
| |
|
inlinestatic |
Definition at line 20900 of file json.hpp.
20902 return parser(detail::input_adapter(
first, last)).sax_parse(sax);
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| size_type nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::size |
( |
void |
| ) |
const |
|
inlinenoexcept |
returns the number of elements
Returns the number of elements in a JSON value.
- Returns
- The return value depends on the different types and is defined as follows:
{The following code calls
size() on the different value types.,size}
Constant, as long as array_t and object_t satisfy the Container concept; that is, their size() functions have constant complexity.
No changes.
No-throw guarantee: this function never throws exceptions.
- Note
- This function does not return the length of a string stored as JSON value - it returns the number of elements in the JSON value which is 1 in the case of a string.
This function helps basic_json satisfying the Container requirements:
- The complexity is constant.
- Has the semantics of
std::distance(begin(), end()).
- See Also
- empty() – checks whether the container is empty
-
max_size() – returns the maximal number of elements
- Since
- version 1.0.0
Definition at line 19195 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
array_t * array
array (stored with pointer to save storage)
array (ordered collection of values)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::swap |
( |
reference |
other | ) |
|
|
inlinenoexcept |
exchanges the values
Exchanges the contents of the JSON value with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
- Parameters
-
| [in,out] | other | JSON value to exchange the contents with |
Constant.
{The example below shows how JSON values can be swapped with swap().,swap__reference}
- Since
- version 1.0.0
Definition at line 20054 of file json.hpp.
20061 std::swap(
m_type, other.m_type);
20062 std::swap(
m_value, other.m_value);
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::swap |
( |
array_t & |
other | ) |
|
|
inline |
exchanges the values
Exchanges the contents of a JSON array with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
- Parameters
-
| [in,out] | other | array to exchange the contents with |
- Exceptions
-
| type_error.310 | when JSON value is not an array; example: "cannot
use swap() with string" |
Constant.
{The example below shows how arrays can be swapped with swap().,swap__array_t}
- Since
- version 1.0.0
Definition at line 20086 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
array_t * array
array (stored with pointer to save storage)
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
constexpr bool is_array() const noexcept
return whether value is an array
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::swap |
( |
object_t & |
other | ) |
|
|
inline |
exchanges the values
Exchanges the contents of a JSON object with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
- Parameters
-
| [in,out] | other | object to exchange the contents with |
- Exceptions
-
| type_error.310 | when JSON value is not an object; example: "cannot use swap() with string" |
Constant.
{The example below shows how objects can be swapped with swap().,swap__object_t}
- Since
- version 1.0.0
Definition at line 20119 of file json.hpp.
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::swap |
( |
string_t & |
other | ) |
|
|
inline |
exchanges the values
Exchanges the contents of a JSON string with those of other. Does not invoke any move, copy, or swap operations on individual elements. All iterators and references remain valid. The past-the-end iterator is invalidated.
- Parameters
-
| [in,out] | other | string to exchange the contents with |
- Exceptions
-
| type_error.310 | when JSON value is not a string; example: "cannot
use swap() with boolean" |
Constant.
{The example below shows how strings can be swapped with swap().,swap__string_t}
- Since
- version 1.0.0
Definition at line 20152 of file json.hpp.
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
string_t * string
string (stored with pointer to save storage)
#define JSON_THROW(exception)
constexpr bool is_string() const noexcept
return whether value is a string
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_bson |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j | ) |
|
|
inlinestatic |
Serializes the given JSON object j to BSON and returns a vector containing the corresponding BSON-representation.
BSON (Binary JSON) is a binary format in which zero or more ordered key/value pairs are stored as a single entity (a so-called document).
The library uses the following mapping from JSON values types to BSON types:
| JSON value type | value/range | BSON type | marker |
| null | null | null | 0x0A |
| boolean | true, false | boolean | 0x08 |
| number_integer | -9223372036854775808..-2147483649 | int64 | 0x12 |
| number_integer | -2147483648..2147483647 | int32 | 0x10 |
| number_integer | 2147483648..9223372036854775807 | int64 | 0x12 |
| number_unsigned | 0..2147483647 | int32 | 0x10 |
| number_unsigned | 2147483648..9223372036854775807 | int64 | 0x12 |
| number_unsigned | 9223372036854775808..18446744073709551615 | – | – |
| number_float | any value | double | 0x01 |
| string | any value | string | 0x02 |
| array | any value | document | 0x04 |
| object | any value | document | 0x03 |
- Warning
- The mapping is incomplete, since only JSON-objects (and things contained therein) can be serialized to BSON. Also, integers larger than 9223372036854775807 cannot be serialized to BSON, and the keys may not contain U+0000, since they are serialized a zero-terminated c-strings.
- Exceptions
-
| out_of_range.407 | if j.is_number_unsigned() && j.get<std::uint64_t>() > 9223372036854775807 |
| out_of_range.409 | if a key in j contains a NULL (U+0000) |
| type_error.317 | if !j.is_object() |
- Precondition
- The input
j is required to be an object: j.is_object() == true.
- Note
- Any BSON output created via to_bson can be successfully parsed by from_bson.
- Parameters
-
| [in] | j | JSON value to serialize |
- Returns
- BSON serialization as byte vector
Linear in the size of the JSON value j.
{The example shows the serialization of a JSON value to a byte vector in BSON format.,to_bson}
- See Also
- http://bsonspec.org/spec.html
-
from_bson(detail::input_adapter&&, const bool strict) for the analogous deserialization
-
to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format
-
to_cbor(const basic_json&) for the related CBOR format
-
to_msgpack(const basic_json&) for the related MessagePack format
Definition at line 21388 of file json.hpp.
21390 std::vector<uint8_t> result;
static std::vector< uint8_t > to_bson(const basic_json &j)
Serializes the given JSON object j to BSON and returns a vector containing the corresponding BSON-rep...
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_bson |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j, |
|
|
detail::output_adapter< uint8_t > |
o |
|
) |
| |
|
inlinestatic |
Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o.
- Parameters
-
| j | The JSON object to convert to BSON. |
| o | The output adapter that receives the binary BSON representation. |
- Precondition
- The input
j shall be an object: j.is_object() == true
- See Also
- to_bson(const basic_json&)
Definition at line 21403 of file json.hpp.
21405 binary_writer<uint8_t>(o).write_bson(j);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_bson |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j, |
|
|
detail::output_adapter< char > |
o |
|
) |
| |
|
inlinestatic |
Serializes the given JSON object j to BSON and forwards the corresponding BSON-representation to the given output_adapter o.
- Parameters
-
| j | The JSON object to convert to BSON. |
| o | The output adapter that receives the binary BSON representation. |
- Precondition
- The input
j shall be an object: j.is_object() == true
- See Also
- to_bson(const basic_json&)
Definition at line 21411 of file json.hpp.
21413 binary_writer<char>(o).write_bson(j);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_cbor |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j | ) |
|
|
inlinestatic |
create a CBOR serialization of a given JSON value
Serializes a given JSON value j to a byte vector using the CBOR (Concise Binary Object Representation) serialization format. CBOR is a binary serialization format which aims to be more compact than JSON itself, yet more efficient to parse.
The library uses the following mapping from JSON values types to CBOR types according to the CBOR specification (RFC 7049):
| JSON value type | value/range | CBOR type | first byte |
| null | null | Null | 0xF6 |
| boolean | true | True | 0xF5 |
| boolean | false | False | 0xF4 |
| number_integer | -9223372036854775808..-2147483649 | Negative integer (8 bytes follow) | 0x3B |
| number_integer | -2147483648..-32769 | Negative integer (4 bytes follow) | 0x3A |
| number_integer | -32768..-129 | Negative integer (2 bytes follow) | 0x39 |
| number_integer | -128..-25 | Negative integer (1 byte follow) | 0x38 |
| number_integer | -24..-1 | Negative integer | 0x20..0x37 |
| number_integer | 0..23 | Integer | 0x00..0x17 |
| number_integer | 24..255 | Unsigned integer (1 byte follow) | 0x18 |
| number_integer | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 |
| number_integer | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A |
| number_integer | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B |
| number_unsigned | 0..23 | Integer | 0x00..0x17 |
| number_unsigned | 24..255 | Unsigned integer (1 byte follow) | 0x18 |
| number_unsigned | 256..65535 | Unsigned integer (2 bytes follow) | 0x19 |
| number_unsigned | 65536..4294967295 | Unsigned integer (4 bytes follow) | 0x1A |
| number_unsigned | 4294967296..18446744073709551615 | Unsigned integer (8 bytes follow) | 0x1B |
| number_float | any value | Double-Precision Float | 0xFB |
| string | length: 0..23 | UTF-8 string | 0x60..0x77 |
| string | length: 23..255 | UTF-8 string (1 byte follow) | 0x78 |
| string | length: 256..65535 | UTF-8 string (2 bytes follow) | 0x79 |
| string | length: 65536..4294967295 | UTF-8 string (4 bytes follow) | 0x7A |
| string | length: 4294967296..18446744073709551615 | UTF-8 string (8 bytes follow) | 0x7B |
| array | size: 0..23 | array | 0x80..0x97 |
| array | size: 23..255 | array (1 byte follow) | 0x98 |
| array | size: 256..65535 | array (2 bytes follow) | 0x99 |
| array | size: 65536..4294967295 | array (4 bytes follow) | 0x9A |
| array | size: 4294967296..18446744073709551615 | array (8 bytes follow) | 0x9B |
| object | size: 0..23 | map | 0xA0..0xB7 |
| object | size: 23..255 | map (1 byte follow) | 0xB8 |
| object | size: 256..65535 | map (2 bytes follow) | 0xB9 |
| object | size: 65536..4294967295 | map (4 bytes follow) | 0xBA |
| object | size: 4294967296..18446744073709551615 | map (8 bytes follow) | 0xBB |
- Note
- The mapping is complete in the sense that any JSON value type can be converted to a CBOR value.
-
If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to
null.
-
The following CBOR types are not used in the conversion:
- byte strings (0x40..0x5F)
- UTF-8 strings terminated by "break" (0x7F)
- arrays terminated by "break" (0x9F)
- maps terminated by "break" (0xBF)
- date/time (0xC0..0xC1)
- bignum (0xC2..0xC3)
- decimal fraction (0xC4)
- bigfloat (0xC5)
- tagged items (0xC6..0xD4, 0xD8..0xDB)
- expected conversions (0xD5..0xD7)
- simple values (0xE0..0xF3, 0xF8)
- undefined (0xF7)
- half and single-precision floats (0xF9-0xFA)
- break (0xFF)
- Parameters
-
| [in] | j | JSON value to serialize |
- Returns
- MessagePack serialization as byte vector
Linear in the size of the JSON value j.
{The example shows the serialization of a JSON value to a byte vector in CBOR format.,to_cbor}
- See Also
- http://cbor.io
-
from_cbor(detail::input_adapter&&, const bool, const bool) for the analogous deserialization
-
to_msgpack(const basic_json&) for the related MessagePack format
-
to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format
- Since
- version 2.0.9
Definition at line 21118 of file json.hpp.
21120 std::vector<uint8_t> result;
static std::vector< uint8_t > to_cbor(const basic_json &j)
create a CBOR serialization of a given JSON value
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_msgpack |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j | ) |
|
|
inlinestatic |
create a MessagePack serialization of a given JSON value
Serializes a given JSON value j to a byte vector using the MessagePack serialization format. MessagePack is a binary serialization format which aims to be more compact than JSON itself, yet more efficient to parse.
The library uses the following mapping from JSON values types to MessagePack types according to the MessagePack specification:
| JSON value type | value/range | MessagePack type | first byte |
| null | null | nil | 0xC0 |
| boolean | true | true | 0xC3 |
| boolean | false | false | 0xC2 |
| number_integer | -9223372036854775808..-2147483649 | int64 | 0xD3 |
| number_integer | -2147483648..-32769 | int32 | 0xD2 |
| number_integer | -32768..-129 | int16 | 0xD1 |
| number_integer | -128..-33 | int8 | 0xD0 |
| number_integer | -32..-1 | negative fixint | 0xE0..0xFF |
| number_integer | 0..127 | positive fixint | 0x00..0x7F |
| number_integer | 128..255 | uint 8 | 0xCC |
| number_integer | 256..65535 | uint 16 | 0xCD |
| number_integer | 65536..4294967295 | uint 32 | 0xCE |
| number_integer | 4294967296..18446744073709551615 | uint 64 | 0xCF |
| number_unsigned | 0..127 | positive fixint | 0x00..0x7F |
| number_unsigned | 128..255 | uint 8 | 0xCC |
| number_unsigned | 256..65535 | uint 16 | 0xCD |
| number_unsigned | 65536..4294967295 | uint 32 | 0xCE |
| number_unsigned | 4294967296..18446744073709551615 | uint 64 | 0xCF |
| number_float | any value | float 64 | 0xCB |
| string | length: 0..31 | fixstr | 0xA0..0xBF |
| string | length: 32..255 | str 8 | 0xD9 |
| string | length: 256..65535 | str 16 | 0xDA |
| string | length: 65536..4294967295 | str 32 | 0xDB |
| array | size: 0..15 | fixarray | 0x90..0x9F |
| array | size: 16..65535 | array 16 | 0xDC |
| array | size: 65536..4294967295 | array 32 | 0xDD |
| object | size: 0..15 | fix map | 0x80..0x8F |
| object | size: 16..65535 | map 16 | 0xDE |
| object | size: 65536..4294967295 | map 32 | 0xDF |
- Note
- The mapping is complete in the sense that any JSON value type can be converted to a MessagePack value.
-
The following values can not be converted to a MessagePack value:
- strings with more than 4294967295 bytes
- arrays with more than 4294967295 elements
- objects with more than 4294967295 elements
-
The following MessagePack types are not used in the conversion:
- bin 8 - bin 32 (0xC4..0xC6)
- ext 8 - ext 32 (0xC7..0xC9)
- float 32 (0xCA)
- fixext 1 - fixext 16 (0xD4..0xD8)
-
Any MessagePack output created to_msgpack can be successfully parsed by from_msgpack.
-
If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to
null.
- Parameters
-
| [in] | j | JSON value to serialize |
- Returns
- MessagePack serialization as byte vector
Linear in the size of the JSON value j.
{The example shows the serialization of a JSON value to a byte vector in MessagePack format.,to_msgpack}
- See Also
- http://msgpack.org
-
from_msgpack for the analogous deserialization
-
to_cbor(const basic_json& for the related CBOR format
-
to_ubjson(const basic_json&, const bool, const bool) for the related UBJSON format
- Since
- version 2.0.9
Definition at line 21214 of file json.hpp.
21216 std::vector<uint8_t> result;
static std::vector< uint8_t > to_msgpack(const basic_json &j)
create a MessagePack serialization of a given JSON value
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| static std::vector<uint8_t> nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::to_ubjson |
( |
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j, |
|
|
const bool |
use_size = false, |
|
|
const bool |
use_type = false |
|
) |
| |
|
inlinestatic |
create a UBJSON serialization of a given JSON value
Serializes a given JSON value j to a byte vector using the UBJSON (Universal Binary JSON) serialization format. UBJSON aims to be more compact than JSON itself, yet more efficient to parse.
The library uses the following mapping from JSON values types to UBJSON types according to the UBJSON specification:
| JSON value type | value/range | UBJSON type | marker |
| null | null | null | Z |
| boolean | true | true | T |
| boolean | false | false | F |
| number_integer | -9223372036854775808..-2147483649 | int64 | L |
| number_integer | -2147483648..-32769 | int32 | l |
| number_integer | -32768..-129 | int16 | I |
| number_integer | -128..127 | int8 | i |
| number_integer | 128..255 | uint8 | U |
| number_integer | 256..32767 | int16 | I |
| number_integer | 32768..2147483647 | int32 | l |
| number_integer | 2147483648..9223372036854775807 | int64 | L |
| number_unsigned | 0..127 | int8 | i |
| number_unsigned | 128..255 | uint8 | U |
| number_unsigned | 256..32767 | int16 | I |
| number_unsigned | 32768..2147483647 | int32 | l |
| number_unsigned | 2147483648..9223372036854775807 | int64 | L |
| number_float | any value | float64 | D |
| string | with shortest length indicator | string | S |
| array | see notes on optimized format | array | [ |
| object | see notes on optimized format | map | { |
- Note
- The mapping is complete in the sense that any JSON value type can be converted to a UBJSON value.
-
The following values can not be converted to a UBJSON value:
- strings with more than 9223372036854775807 bytes (theoretical)
- unsigned integer numbers above 9223372036854775807
-
The following markers are not used in the conversion:
Z: no-op values are not created.C: single-byte strings are serialized with S markers.
-
Any UBJSON output created to_ubjson can be successfully parsed by from_ubjson.
-
If NaN or Infinity are stored inside a JSON number, they are serialized properly. This behavior differs from the dump() function which serializes NaN or Infinity to
null.
-
The optimized formats for containers are supported: Parameter use_size adds size information to the beginning of a container and removes the closing marker. Parameter use_type further checks whether all elements of a container have the same type and adds the type marker to the beginning of the container. The use_type parameter must only be used together with use_size = true. Note that use_size = true alone may result in larger representations - the benefit of this parameter is that the receiving side is immediately informed on the number of elements of the container.
- Parameters
-
| [in] | j | JSON value to serialize |
| [in] | use_size | whether to add size annotations to container types |
| [in] | use_type | whether to add type annotations to container types (must be combined with use_size = true) |
- Returns
- UBJSON serialization as byte vector
Linear in the size of the JSON value j.
{The example shows the serialization of a JSON value to a byte vector in UBJSON format.,to_ubjson}
- See Also
- http://ubjson.org
-
from_ubjson(detail::input_adapter&&, const bool, const bool) for the analogous deserialization
-
to_cbor(const basic_json& for the related CBOR format
-
to_msgpack(const basic_json&) for the related MessagePack format
- Since
- version 3.1.0
Definition at line 21311 of file json.hpp.
21315 std::vector<uint8_t> result;
21316 to_ubjson(j, result, use_size, use_type);
static std::vector< uint8_t > to_ubjson(const basic_json &j, const bool use_size=false, const bool use_type=false)
create a UBJSON serialization of a given JSON value
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| constexpr value_t nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::type |
( |
| ) |
const |
|
inlinenoexcept |
return the type of the JSON value (explicit)
Return the type of the JSON value as a value from the value_t enumeration.
- Returns
- the type of the JSON value
Constant.
No-throw guarantee: this member function never throws exceptions.
{The following code exemplifies type() for all JSON types.,type}
- See Also
- operator value_t() – return the type of the JSON value (implicit)
-
type_name() – return the type as string
- Since
- version 1.0.0
Definition at line 16612 of file json.hpp.
value_t m_type
the type of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
return the type as string
Returns the type name as string to be used in error messages - usually to indicate that a function was called on a wrong JSON type.
- Returns
- a string representation of a the m_type member:
| Value type | return value |
| null | "null" |
| boolean | "boolean" |
| string | "string" |
| number | "number" (for all number types) |
| object | "object" |
| array | "array" |
| discarded | "discarded" |
No-throw guarantee: this function never throws exceptions.
Constant.
{The following code exemplifies type_name() for all JSON types.,type_name}
- See Also
- type() – return the type of the JSON value
-
operator value_t() – return the type of the JSON value (implicit)
- Since
- version 1.0.0, public since 2.1.0,
const char* and noexcept since 3.0.0
Definition at line 20987 of file json.hpp.
21003 return "discarded";
array (ordered collection of values)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
discarded by the the parser callback function
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| basic_json nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::unflatten |
( |
| ) |
const |
|
inline |
unflatten a previously flattened JSON value
The function restores the arbitrary nesting of a JSON value that has been flattened before using the flatten() function. The JSON value must meet certain constraints:
- The value must be an object.
- The keys must be JSON pointers (see RFC 6901)
- The mapped values must be primitive JSON types.
- Returns
- the original JSON from a flattened version
- Note
- Empty objects and arrays are flattened by flatten() to
null values and can not unflattened to their original type. Apart from this example, for a JSON value j, the following is always true: j == j.flatten().unflatten().
Linear in the size the JSON value.
- Exceptions
-
| type_error.314 | if value is not an object |
| type_error.315 | if object values are not primitive |
{The following code shows how a flattened JSON object is unflattened into the original nested JSON object.,unflatten}
- See Also
- flatten() for the reverse function
- Since
- version 2.0.0
Definition at line 22049 of file json.hpp.
static BasicJsonType unflatten(const BasicJsonType &value)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| void nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::update |
( |
const_reference |
j | ) |
|
|
inline |
updates a JSON object from another object, overwriting existing keys
Inserts all values from JSON object j and overwrites existing keys.
- Parameters
-
| [in] | j | JSON object to read values from |
- Exceptions
-
| type_error.312 | if called on JSON values other than objects; example: "cannot use update() with string" |
O(N*log(size() + N)), where N is the number of elements to insert.
{The example shows how update() is used.,update}
- See Also
- https://docs.python.org/3.6/library/stdtypes.html#dict.update
- Since
- version 3.0.0
Definition at line 19952 of file json.hpp.
19971 for (
auto it = j.cbegin(); it != j.cend(); ++it)
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
updates a JSON object from another object, overwriting existing keys
Inserts all values from from range [first, last) and overwrites existing keys.
- Parameters
-
| [in] | first | begin of the range of elements to insert |
| [in] | last | end of the range of elements to insert |
- Exceptions
-
| type_error.312 | if called on JSON values other than objects; example: "cannot use update() with string" |
| invalid_iterator.202 | if iterator first or last does does not point to an object; example: "iterators first and last must point to
objects" |
| invalid_iterator.210 | if first and last do not belong to the same JSON value; example: "iterators do not fit" |
O(N*log(size() + N)), where N is the number of elements to insert.
{The example shows how update() is used__range.,update}
- See Also
- https://docs.python.org/3.6/library/stdtypes.html#dict.update
- Since
- version 3.0.0
Definition at line 20003 of file json.hpp.
20026 or not last.m_object->is_object()))
20031 for (
auto it =
first; it != last; ++it)
object_t * object
object (stored with pointer to save storage)
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
constexpr bool is_object() const noexcept
return whether value is an object
constexpr bool is_null() const noexcept
return whether value is null
#define JSON_THROW(exception)
object (unordered set of name/value pairs)
value_t m_type
the type of the current element
void assert_invariant() const noexcept
checks the class invariants
static invalid_iterator create(int id_, const std::string &what_arg)
#define JSON_HEDLEY_UNLIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
json_value m_value
the value of the current element
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class ValueType , typename std::enable_if< std::is_convertible< basic_json_t, ValueType >::value, int >::type = 0>
| ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::value |
( |
const typename object_t::key_type & |
key, |
|
|
const ValueType & |
default_value |
|
) |
| const |
|
inline |
access specified object element with default value
Returns either a copy of an object's element at the specified key key or a given default value if no element with key key exists.
The function is basically equivalent to executing
try {
return default_value;
}
- Note
- Unlike at(const typename object_t::key_type&), this function does not throw if the given key key was not found.
-
Unlike operator[](const typename object_t::key_type& key), this function does not implicitly add an element to the position defined by key. This function is furthermore also applicable to const objects.
- Parameters
-
| [in] | key | key of the element to access |
| [in] | default_value | the value to return if key is not found |
- Template Parameters
-
| ValueType | type compatible to JSON values, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. Note the type of the expected value at key and the default value default_value must be compatible. |
- Returns
- copy of the element at key key or default_value if key is not found
- Exceptions
-
| type_error.302 | if default_value does not match the type of the value at key |
| type_error.306 | if the JSON value is not an object; in that case, using value() with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be queried with a default value.,basic_json__value}
- See Also
- at(const typename object_t::key_type&) for access by reference with range checking
-
operator[](const typename object_t::key_type&) for unchecked access by reference
- Since
- version 1.0.0
Definition at line 18003 of file json.hpp.
18009 const auto it =
find(key);
18015 return default_value;
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
iterator end() noexcept
returns an iterator to one past the last element
constexpr bool is_object() const noexcept
return whether value is an object
iterator find(KeyT &&key)
find an element in a JSON object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<class ValueType , typename std::enable_if< std::is_convertible< basic_json_t, ValueType >::value, int >::type = 0>
| ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::value |
( |
const json_pointer & |
ptr, |
|
|
const ValueType & |
default_value |
|
) |
| const |
|
inline |
access specified object element via JSON Pointer with default value
Returns either a copy of an object's element at the specified key key or a given default value if no element with key key exists.
The function is basically equivalent to executing
try {
return default_value;
}
- Note
- Unlike at(const json_pointer&), this function does not throw if the given key key was not found.
- Parameters
-
| [in] | ptr | a JSON pointer to the element to access |
| [in] | default_value | the value to return if ptr found no value |
- Template Parameters
-
| ValueType | type compatible to JSON values, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. Note the type of the expected value at key and the default value default_value must be compatible. |
- Returns
- copy of the element at key key or default_value if key is not found
- Exceptions
-
| type_error.302 | if default_value does not match the type of the value at ptr |
| type_error.306 | if the JSON value is not an object; in that case, using value() with a key makes no sense. |
Logarithmic in the size of the container.
{The example below shows how object elements can be queried with a default value.,basic_json__value_ptr}
- See Also
- operator[](const json_pointer&) for unchecked access by reference
- Since
- version 2.0.2
Definition at line 18075 of file json.hpp.
18083 return ptr.get_checked(
this);
18087 return default_value;
JSON_HEDLEY_RETURNS_NON_NULL const char * type_name() const noexcept
return the type as string
#define JSON_INTERNAL_CATCH(exception)
constexpr bool is_object() const noexcept
return whether value is an object
#define JSON_THROW(exception)
#define JSON_HEDLEY_LIKELY(expr)
detail::out_of_range out_of_range
exception indicating access out of the defined range
static type_error create(int id_, const std::string &what_arg)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType , typename SAX >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType , typename CharType >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename BasicJsonType >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<detail::value_t >
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: not equal
Compares two JSON values for inequality by calculating not (lhs == rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are not equal
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__notequal}
- Since
- version 1.0.0
Definition at line 20319 of file json.hpp.
20321 return not (lhs == rhs);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: not equal
comparison: not equal Compares two JSON values for inequality by calculating not (lhs == rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are not equal
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__notequal}
- Since
- version 1.0.0
Definition at line 20330 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: not equal
comparison: not equal Compares two JSON values for inequality by calculating not (lhs == rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are not equal
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__notequal}
- Since
- version 1.0.0
Definition at line 20341 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: less than
Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:
- If lhs and rhs have the same type, the values are compared using the default
< operator.
- Integer and floating-point numbers are automatically converted before comparison
- In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__less}
- Since
- version 1.0.0
Definition at line 20372 of file json.hpp.
20374 const auto lhs_type = lhs.type();
20375 const auto rhs_type = rhs.type();
20377 if (lhs_type == rhs_type)
20384 return (*lhs.m_value.array) < (*rhs.m_value.array);
20387 return (*lhs.m_value.object) < (*rhs.m_value.object);
20393 return (*lhs.m_value.string) < (*rhs.m_value.string);
20396 return (lhs.m_value.boolean) < (rhs.m_value.boolean);
20399 return (lhs.m_value.number_integer) < (rhs.m_value.number_integer);
20402 return (lhs.m_value.number_unsigned) < (rhs.m_value.number_unsigned);
20405 return (lhs.m_value.number_float) < (rhs.m_value.number_float);
20413 return static_cast<number_float_t>(lhs.m_value.number_integer) < rhs.m_value.number_float;
20417 return lhs.m_value.number_float <
static_cast<number_float_t>(rhs.m_value.number_integer);
20421 return static_cast<number_float_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_float;
20425 return lhs.m_value.number_float <
static_cast<number_float_t>(rhs.m_value.number_unsigned);
20429 return lhs.m_value.number_integer <
static_cast<number_integer_t>(rhs.m_value.number_unsigned);
20433 return static_cast<number_integer_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_integer;
friend bool operator<(const_reference lhs, const_reference rhs) noexcept
comparison: less than
NumberFloatType number_float_t
a type for a number (floating-point)
array (ordered collection of values)
NumberIntegerType number_integer_t
a type for a number (integer)
number value (signed integer)
object (unordered set of name/value pairs)
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
number value (unsigned integer)
number value (floating-point)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: less than
comparison: less than Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:
- If lhs and rhs have the same type, the values are compared using the default
< operator.
- Integer and floating-point numbers are automatically converted before comparison
- In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__less}
- Since
- version 1.0.0
Definition at line 20448 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: less than
comparison: less than Compares whether one JSON value lhs is less than another JSON value rhs according to the following rules:
- If lhs and rhs have the same type, the values are compared using the default
< operator.
- Integer and floating-point numbers are automatically converted before comparison
- In case lhs and rhs have different types, the values are ignored and the order of the types is considered, see operator<(const value_t, const value_t).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__less}
- Since
- version 1.0.0
Definition at line 20459 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| std::ostream& operator<< |
( |
std::ostream & |
o, |
|
|
const basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j |
|
) |
| |
|
friend |
serialize to stream
Serialize the given JSON value j to the output stream o. The JSON value will be serialized using the dump member function.
- The indentation of the output can be controlled with the member variable
width of the output stream o. For instance, using the manipulator std::setw(4) on o sets the indentation level to 4 and the serialization result is the same as calling dump(4).
- The indentation character can be controlled with the member variable
fill of the output stream o. For instance, the manipulator `std::setfill('\t')` sets indentation to use a tab character rather than the default space character.
- Parameters
-
| [in,out] | o | stream to serialize to |
| [in] | j | JSON value to serialize |
- Returns
- the stream o
- Exceptions
-
| type_error.316 | if a string stored inside the JSON value is not UTF-8 encoded |
Linear.
{The example below shows the serialization with different parameters to width to adjust the indentation level.,operator_serialize}
- Since
- version 1.0.0; indentation character added in version 3.0.0
Definition at line 20642 of file json.hpp.
20645 const bool pretty_print = o.width() > 0;
20646 const auto indentation = pretty_print ? o.width() : 0;
20652 serializer s(detail::output_adapter<char>(o), o.fill());
20653 s.dump(j, pretty_print,
false, static_cast<unsigned int>(indentation));
::nlohmann::detail::serializer< basic_json > serializer
then echo File list $list not found else cat $list while read file do echo $file sed s
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: less than or equal
Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greater}
- Since
- version 1.0.0
Definition at line 20483 of file json.hpp.
20485 return not (rhs < lhs);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: less than or equal
comparison: less than or equal Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greater}
- Since
- version 1.0.0
Definition at line 20494 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: less than or equal
comparison: less than or equal Compares whether one JSON value lhs is less than or equal to another JSON value by calculating not (rhs < lhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is less than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greater}
- Since
- version 1.0.0
Definition at line 20505 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: equal
Compares two JSON values for equality according to the following rules:
- Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective
operator==.
- Integer and floating-point numbers are automatically converted before comparison. Note than two NaN values are always treated as unequal.
- Two JSON null values are equal.
- Note
- Floating-point inside JSON values numbers are compared with
json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
inline bool is_same(T
a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
}
-
NaN values never compare equal to themselves or to other NaN values.
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are equal
No-throw guarantee: this function never throws exceptions.
Linear.
{The example demonstrates comparing several JSON types.,operator__equal}
- Since
- version 1.0.0
Definition at line 20214 of file json.hpp.
20216 const auto lhs_type = lhs.type();
20217 const auto rhs_type = rhs.type();
20219 if (lhs_type == rhs_type)
20224 return *lhs.m_value.array == *rhs.m_value.array;
20227 return *lhs.m_value.object == *rhs.m_value.object;
20233 return *lhs.m_value.string == *rhs.m_value.string;
20236 return lhs.m_value.boolean == rhs.m_value.boolean;
20239 return lhs.m_value.number_integer == rhs.m_value.number_integer;
20242 return lhs.m_value.number_unsigned == rhs.m_value.number_unsigned;
20245 return lhs.m_value.number_float == rhs.m_value.number_float;
20253 return static_cast<number_float_t>(lhs.m_value.number_integer) == rhs.m_value.number_float;
20257 return lhs.m_value.number_float ==
static_cast<number_float_t>(rhs.m_value.number_integer);
20261 return static_cast<number_float_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_float;
20265 return lhs.m_value.number_float ==
static_cast<number_float_t>(rhs.m_value.number_unsigned);
20269 return static_cast<number_integer_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_integer;
20273 return lhs.m_value.number_integer ==
static_cast<number_integer_t>(rhs.m_value.number_unsigned);
NumberFloatType number_float_t
a type for a number (floating-point)
array (ordered collection of values)
NumberIntegerType number_integer_t
a type for a number (integer)
number value (signed integer)
object (unordered set of name/value pairs)
return match has_match and(match.match_pdg==11 or match.match_pdg==-11)
number value (unsigned integer)
number value (floating-point)
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: equal
comparison: equal Compares two JSON values for equality according to the following rules:
- Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective
operator==.
- Integer and floating-point numbers are automatically converted before comparison. Note than two NaN values are always treated as unequal.
- Two JSON null values are equal.
- Note
- Floating-point inside JSON values numbers are compared with
json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
inline bool is_same(T
a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
}
-
NaN values never compare equal to themselves or to other NaN values.
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are equal
No-throw guarantee: this function never throws exceptions.
Linear.
{The example demonstrates comparing several JSON types.,operator__equal}
- Since
- version 1.0.0
Definition at line 20285 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: equal
comparison: equal Compares two JSON values for equality according to the following rules:
- Two JSON values are equal if (1) they are from the same type and (2) their stored values are the same according to their respective
operator==.
- Integer and floating-point numbers are automatically converted before comparison. Note than two NaN values are always treated as unequal.
- Two JSON null values are equal.
- Note
- Floating-point inside JSON values numbers are compared with
json::number_float_t::operator== which is double::operator== by default. To compare floating-point while respecting an epsilon, an alternative comparison function could be used, for instance
inline bool is_same(T
a, T b, T epsilon = std::numeric_limits<T>::epsilon()) noexcept
{
}
-
NaN values never compare equal to themselves or to other NaN values.
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether the values lhs and rhs are equal
No-throw guarantee: this function never throws exceptions.
Linear.
{The example demonstrates comparing several JSON types.,operator__equal}
- Since
- version 1.0.0
Definition at line 20296 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: greater than
Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__lessequal}
- Since
- version 1.0.0
Definition at line 20529 of file json.hpp.
20531 return not (lhs <= rhs);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: greater than
comparison: greater than Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__lessequal}
- Since
- version 1.0.0
Definition at line 20540 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: greater than
comparison: greater than Compares whether one JSON value lhs is greater than another JSON value by calculating not (lhs <= rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__lessequal}
- Since
- version 1.0.0
Definition at line 20551 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
comparison: greater than or equal
Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greaterequal}
- Since
- version 1.0.0
Definition at line 20575 of file json.hpp.
20577 return not (lhs < rhs);
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: greater than or equal
comparison: greater than or equal Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greaterequal}
- Since
- version 1.0.0
Definition at line 20586 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
template<typename ScalarType , typename std::enable_if< std::is_scalar< ScalarType >::value, int >::type = 0>
comparison: greater than or equal
comparison: greater than or equal Compares whether one JSON value lhs is greater than or equal to another JSON value by calculating not (lhs < rhs).
- Parameters
-
| [in] | lhs | first JSON value to consider |
| [in] | rhs | second JSON value to consider |
- Returns
- whether lhs is greater than or equal to rhs
Linear.
No-throw guarantee: this function never throws exceptions.
{The example demonstrates comparing several JSON types.,operator__greaterequal}
- Since
- version 1.0.0
Definition at line 20597 of file json.hpp.
basic_json(const value_t v)
create an empty value with a given type
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| std::istream& operator>> |
( |
std::istream & |
i, |
|
|
basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer > & |
j |
|
) |
| |
|
friend |
deserialize from stream
Deserializes an input stream to a JSON value.
- Parameters
-
| [in,out] | i | input stream to read a serialized JSON value from |
| [in,out] | j | JSON value to write the deserialized input to |
- Exceptions
-
| parse_error.101 | in case of an unexpected token |
| parse_error.102 | if to_unicode fails or surrogate error |
| parse_error.103 | if to_unicode fails |
Linear in the length of the input. The parser is a predictive LL(1) parser.
- Note
- A UTF-8 byte order mark is silently ignored.
{The example below shows how a JSON value is constructed by reading a serialization from a stream.,operator_deserialize}
- See Also
- parse(std::istream&, const parser_callback_t) for a variant with a parser callback function to filter values while parsing
- Since
- version 1.0.0
Definition at line 20944 of file json.hpp.
20946 parser(detail::input_adapter(i)).parse(
false, j);
::nlohmann::detail::parser< basic_json > parser
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
the type of the current element
Definition at line 21017 of file json.hpp.
template<template< typename U, typename V, typename...Args > class ObjectType = std::map, template< typename U, typename...Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer>
| json_value nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer >::m_value = {} |
|
private |
the value of the current element
Definition at line 21020 of file json.hpp.
1.8.5