util::flags Namespace Reference

Classes and functions to manage bit masks and flags. More...

Namespaces
	details
	errors
	Namespace enclosing BitMask exceptions.

Classes
struct	Flag_t
	Type identifying a flag. Operations are implemented as free functions. More...
struct	Bits_t
	Type identifying a set of bits. More...
struct	BitMaskFromValuesTag
	Type for constructor tag from values. More...
class	BitMask
	A class containing a set of flags. More...
class	FlagSet
	A class containing a set of flags. More...

Typedefs
using	Index_t = unsigned int
	Type to denote the index of the flag. More...

Functions
template<typename Storage >
std::ostream &	operator<< (std::ostream &out, Flag_t< Storage > flag)
	Output of a flag into a stream (prints its index). More...
template<typename Storage >
std::string	to_string (Flag_t< Storage > const flag)
	Convert a flag into a stream (shows its index). More...
template<typename Stream , typename Storage >
Stream &	operator<< (Stream &&out, BitMask< Storage > const &mask)
	Output of a bit mask into a stream. More...
template<typename Storage >
constexpr BitMask< Storage >	makeMask (Bits_t< Storage > bits)
	Constructs a mask from bits. More...
template<unsigned int NBits, typename Storage >
std::ostream &	operator<< (std::ostream &out, FlagSet< NBits, Storage > const &flags)
	Output of a flag set into a stream. More...
Comparison operators for flags (based on the index)
template<typename Storage >
constexpr bool	operator== (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator== (Flag_t< Storage > left, Index_t right)
template<typename Storage >
constexpr bool	operator!= (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator!= (Flag_t< Storage > left, Index_t right)
template<typename Storage >
constexpr bool	operator< (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator< (Flag_t< Storage > left, Index_t right)
template<typename Storage >
constexpr bool	operator> (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator> (Flag_t< Storage > left, Index_t right)
template<typename Storage >
constexpr bool	operator<= (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator<= (Flag_t< Storage > left, Index_t right)
template<typename Storage >
constexpr bool	operator>= (Index_t left, Flag_t< Storage > right)
template<typename Storage >
constexpr bool	operator>= (Flag_t< Storage > left, Index_t right)
Flag and bit operations.
Any bitwise operation with a flag returns a Bits_t.
template<typename Storage >
constexpr Bits_t< Storage >	operator| (Bits_t< Storage > left, Bits_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator| (Bits_t< Storage > left, typename Bits_t< Storage >::Flag_t right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator| (typename Bits_t< Storage >::Flag_t left, Bits_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator| (Flag_t< Storage > left, Flag_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator+ (Bits_t< Storage > left, Bits_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator+ (Bits_t< Storage > left, typename Bits_t< Storage >::Flag_t right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator+ (typename Bits_t< Storage >::Flag_t left, Bits_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
template<typename Storage >
constexpr Bits_t< Storage >	operator+ (Flag_t< Storage > left, Flag_t< Storage > right)
	Returns a new Bits_t with all the bits from both arguments set. More...
Flag and mask management
The operations use the first operand as the starting point for the result. The binary operations in this group are: bit-wise OR (equivalent to combineWithMask()) bit-wise AND (equivalent to intersectWithMask()) addition: the flags of the right operand that are defined are copied into the result subtraction: the flags of the right operand that are set are unset in the result The unary operations are: bitwise negation (equivalent to negateMask()) unary plus sign: no operation (bit it converts the operand to Mask_t) unary minus sign is not defined
template<typename Storage >
constexpr BitMask< Storage >	operator| (BitMask< Storage > left, BitMask< Storage > right)
template<typename Storage >
constexpr BitMask< Storage >	operator| (BitMask< Storage > left, typename BitMask< Storage >::Bits_t right)
template<typename Storage >
constexpr BitMask< Storage >	operator| (typename BitMask< Storage >::Bits_t left, BitMask< Storage > right)
template<typename Storage >
constexpr BitMask< Storage >	operator& (BitMask< Storage > left, BitMask< Storage > right)
template<typename Storage >
constexpr BitMask< Storage >	operator& (BitMask< Storage > left, typename BitMask< Storage >::Bits_t right)
template<typename Storage >
constexpr BitMask< Storage >	operator& (typename BitMask< Storage >::Bits_t left, BitMask< Storage > right)
template<typename Storage >
constexpr BitMask< Storage >	operator& (Bits_t< Storage > left, Bits_t< Storage > right)
template<typename Storage >
constexpr BitMask< Storage >	operator+ (BitMask< Storage > baseMask, BitMask< Storage > mask)
template<typename Storage >
constexpr BitMask< Storage >	operator+ (BitMask< Storage > baseMask, typename BitMask< Storage >::Bits_t bits)
template<typename Storage >
constexpr BitMask< Storage >	operator+ (typename BitMask< Storage >::Bits_t baseBits, BitMask< Storage > mask)
template<typename Storage >
constexpr BitMask< Storage >	operator- (BitMask< Storage > baseMask, BitMask< Storage > mask)
template<typename Storage >
constexpr BitMask< Storage >	operator- (BitMask< Storage > baseMask, typename BitMask< Storage >::Bits_t bits)
template<typename Storage >
constexpr BitMask< Storage >	operator- (typename BitMask< Storage >::Bits_t baseBits, BitMask< Storage > mask)
template<typename Storage >
constexpr BitMask< Storage >	operator- (Bits_t< Storage > baseBits, Bits_t< Storage > bits)
template<typename Storage >
constexpr BitMask< Storage >	operator+ (BitMask< Storage > mask)
	Returns a copy of the mask. More...
template<typename Storage >
constexpr BitMask< Storage >	operator+ (Bits_t< Storage > bits)
	Returns a mask with the specified bits set. More...
template<typename Storage >
constexpr BitMask< Storage >	operator- (Bits_t< Storage > bits)
	Returns a mask M = -B so that A + M is equivalent to A - B. More...
template<typename Storage >
constexpr BitMask< Storage >	operator- (Flag_t< Storage > flag)
	Returns a mask M = -B so that A + M is equivalent to A - B. More...
template<typename Storage >
constexpr BitMask< Storage >	operator~ (BitMask< Storage > mask)
	Returns a bit set which unsets the specified bits. More...
template<typename Storage >
constexpr BitMask< Storage >	Set (Flag_t< Storage > flag)
	Returns a bit mask which sets the specified flag. More...
template<typename Storage >
constexpr BitMask< Storage >	Unset (Flag_t< Storage > flag)
	Returns a bit mask which unsets the specified flag. More...

Variables
constexpr BitMaskFromValuesTag	maskFromValues {}
	Value useful for BitMask constructors from value. More...

Detailed Description

Classes and functions to manage bit masks and flags.

In this namespace a "hierarchy" of classes are defined:

• Flag_t: a single bit; it can be initialized with the bit index, but it is stored as a bit mask. A flag has two states: set and unset.
• Bits_t: a set of flags (represented as a bit mask).
• BitMask: a set of flags which can have one of three states each: set, unset or undefined.
• FlagSet: a set of flags (like BitMask), with the knowledge of a total number of supported flags.

The first three classes manage exactly how many bits they have storage for. FlagSet instead has also the notion of how many flags are actually supported. A number of flag-wise operations are defined. The result of an operation between two classes might be a class of a superior level in the hierarchy. In this sense, the lower objects should be intended as shortcut representations of Bits_t. More specifically:

• a Bits_t can be created out of a Flag_t
• a BitMask can be created out of a Bits_t (or a Flag_t)
• ~Flag_t is not defined
• Bits_t | Bits_t and Bits_t + Bits_t are still Bits_t (and they are equivalent)
• Bits_t & Bits_t and Bits_t - Bits_t are BitMask, to preserve the information of bits that are defined and unset
• ~Bits_t is a BitMask as well

Typedef Documentation

using util::flags::Index_t = typedef unsigned int

Type to denote the index of the flag.

Definition at line 60 of file BitMask.h.

Function Documentation

template<typename Storage >

constexpr BitMask<Storage> util::flags::makeMask

(

Bits_t< Storage >

bits

)

Constructs a mask from bits.

template<typename Storage >

constexpr bool util::flags::operator!=	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 144 of file BitMask.h.

      { return left != right.index(); }

template<typename Storage >

constexpr bool util::flags::operator!=	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 147 of file BitMask.h.

      { return left.index() != right; }

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator&	(	BitMask< Storage >	left,
		BitMask< Storage >	right
	)

Returns a mask which intersects two of them.

See Also

BitMask<Storage>::intersectWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator&	(	BitMask< Storage >	left,
		typename BitMask< Storage >::Bits_t	right
	)

Returns a mask which intersects two of them.

See Also

BitMask<Storage>::intersectWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator&	(	typename BitMask< Storage >::Bits_t	left,
		BitMask< Storage >	right
	)

Returns a mask which intersects two of them.

See Also

BitMask<Storage>::intersectWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator&	(	Bits_t< Storage >	left,
		Bits_t< Storage >	right
	)

Returns a mask which intersects two of them.

See Also

BitMask<Storage>::intersectWithMask()

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator+	(	Bits_t< Storage >	left,
		Bits_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator+	(	Bits_t< Storage >	left,
		typename Bits_t< Storage >::Flag_t	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator+	(	typename Bits_t< Storage >::Flag_t	left,
		Bits_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator+	(	Flag_t< Storage >	left,
		Flag_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator+	(	BitMask< Storage >	baseMask,
		BitMask< Storage >	mask
	)

Returns a mask which merges two of them.

See Also

BitMask<Storage>::mergeIntoMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator+	(	BitMask< Storage >	baseMask,
		typename BitMask< Storage >::Bits_t	bits
	)

Returns a mask which merges two of them

See Also

BitMask<Storage>::mergeIntoMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator+	(	typename BitMask< Storage >::Bits_t	baseBits,
		BitMask< Storage >	mask
	)

Returns a mask which merges two of them

See Also

BitMask<Storage>::mergeIntoMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator+

(

BitMask< Storage >

mask

)

Returns a copy of the mask.

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator+

(

Bits_t< Storage >

bits

)

Returns a mask with the specified bits set.

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-	(	BitMask< Storage >	baseMask,
		BitMask< Storage >	mask
	)

Returns a mask set which defines and unsets the bits set in the mask.

See Also

BitMask<Storage>::unsetMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-	(	BitMask< Storage >	baseMask,
		typename BitMask< Storage >::Bits_t	bits
	)

Returns a mask set which defines and unsets the specified bits.

See Also

BitMask<Storage>::unsetMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-	(	typename BitMask< Storage >::Bits_t	baseBits,
		BitMask< Storage >	mask
	)

Returns a mask set which defines and unsets the bits set in the mask.

See Also

BitMask<Storage>::unsetMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-	(	Bits_t< Storage >	baseBits,
		Bits_t< Storage >	bits
	)

Returns a mask which defines and unsets the specified bits.

See Also

BitMask<Storage>::unsetMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-

(

Bits_t< Storage >

bits

)

Returns a mask M = -B so that A + M is equivalent to A - B.

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator-

(

Flag_t< Storage >

flag

)

Returns a mask M = -B so that A + M is equivalent to A - B.

template<typename Storage >

constexpr bool util::flags::operator<	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 151 of file BitMask.h.

      { return left < right.index(); }

template<typename Storage >

constexpr bool util::flags::operator<	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 154 of file BitMask.h.

      { return left.index() < right; }

template<typename Storage >

std::ostream& util::flags::operator<<	(	std::ostream &	out,
		Flag_t< Storage >	flag
	)

Output of a flag into a stream (prints its index).

Definition at line 182 of file BitMask.h.

      { out << '[' << flag.index() << ']'; return out; }

template<unsigned int NBits, typename Storage >

std::ostream& util::flags::operator<<	(	std::ostream &	out,
		FlagSet< NBits, Storage > const &	flags
	)

Output of a flag set into a stream.

Definition at line 196 of file FlagSet.h.

      { flags.dump(out); return out; }

template<typename Stream , typename Storage >

Stream& util::flags::operator<<	(	Stream &&	out,
		BitMask< Storage > const &	mask
	)

Output of a bit mask into a stream.

Definition at line 1203 of file BitMask.h.

      { mask.dump(std::forward<Stream>(out)); return out; }

template<typename Storage >

constexpr bool util::flags::operator<=	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 165 of file BitMask.h.

      { return left <= right.index(); }

template<typename Storage >

constexpr bool util::flags::operator<=	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 168 of file BitMask.h.

      { return left.index() <= right; }

template<typename Storage >

constexpr bool util::flags::operator==	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 137 of file BitMask.h.

      { return left == right.index(); }

template<typename Storage >

constexpr bool util::flags::operator==	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 140 of file BitMask.h.

      { return left.index() == right; }

template<typename Storage >

constexpr bool util::flags::operator>	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 158 of file BitMask.h.

      { return left > right.index(); }

template<typename Storage >

constexpr bool util::flags::operator>	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 161 of file BitMask.h.

      { return left.index() > right; }

template<typename Storage >

constexpr bool util::flags::operator>=	(	Index_t	left,
		Flag_t< Storage >	right
	)

Definition at line 172 of file BitMask.h.

      { return left >= right.index(); }

template<typename Storage >

constexpr bool util::flags::operator>=	(	Flag_t< Storage >	left,
		Index_t	right
	)

Definition at line 175 of file BitMask.h.

      { return left.index() >= right; }

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator|	(	Bits_t< Storage >	left,
		Bits_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator|	(	Bits_t< Storage >	left,
		typename Bits_t< Storage >::Flag_t	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator|	(	typename Bits_t< Storage >::Flag_t	left,
		Bits_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr Bits_t<Storage> util::flags::operator|	(	Flag_t< Storage >	left,
		Flag_t< Storage >	right
	)

Returns a new Bits_t with all the bits from both arguments set.

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator|	(	BitMask< Storage >	left,
		BitMask< Storage >	right
	)

Returns a mask which combines two of them.

See Also

BitMask<Storage>::combineWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator|	(	BitMask< Storage >	left,
		typename BitMask< Storage >::Bits_t	right
	)

Returns a mask which merges two of them.

See Also

BitMask<Storage>::combineWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator|	(	typename BitMask< Storage >::Bits_t	left,
		BitMask< Storage >	right
	)

Returns a mask which merges two of them.

See Also

BitMask<Storage>::combineWithMask()

template<typename Storage >

constexpr BitMask<Storage> util::flags::operator~

(

BitMask< Storage >

mask

)

Returns a bit set which unsets the specified bits.

template<typename Storage >

constexpr BitMask<Storage> util::flags::Set

(

Flag_t< Storage >

flag

)

Returns a bit mask which sets the specified flag.

template<typename Storage >

std::string util::flags::to_string

(

Flag_t< Storage > const

flag

)

Convert a flag into a stream (shows its index).

Definition at line 187 of file BitMask.h.

      { return std::to_string(flag.index()); }

template<typename Storage >

constexpr BitMask<Storage> util::flags::Unset

(

Flag_t< Storage >

flag

)

Returns a bit mask which unsets the specified flag.

Variable Documentation

constexpr BitMaskFromValuesTag util::flags::maskFromValues {}

Value useful for BitMask constructors from value.

Definition at line 404 of file BitMask.h.