lar Namespace Reference

LArSoft-specific namespace. More...

Namespaces
	debug
	details
	Namespace hiding implementation details.
	dump
	Namespace for LArSoft dumping utilities.
	example
	LArSoft examples.
	fhicl
	LArSoft utilities for interface with FHiCL and its libraries.
	standalone
	Utilities for use in an environment without art.
	test
	util
	LArSoft utility namespace.

Classes
class	EnsureOnlyOneSchedule
class	SimpleServiceProviderWrapper
	Service returning a provider. More...
class	ServiceProviderInterfaceWrapper
	Service returning a provider interface. More...
class	ServiceProviderImplementationWrapper
	Service implementation returning a provider. More...
class	ProviderPack
	Container for a list of pointers to providers. More...
struct	UncopiableClass
	An empty class that can't be copied (moving is allowed). More...
struct	UnmovableClass
	An empty class that can't be moved (copy is allowed). More...
struct	UncopiableAndUnmovableClass
	An empty class that can't be copied nor moved. More...
struct	PolymorphicClass
	A simple polymorphic class, providing a virtual table. More...
struct	PolymorphicUncopiableClass
	A polymorphic empty class that can't be copied (moving is allowed). More...
struct	PolymorphicUnmovableClass
	An empty polymorphic class that can't be moved (copy is allowed). More...
struct	PolymorphicUncopiableAndUnmovableClass
	An empty class that can't be copied nor moved. More...
class	OptionalHexFloat
	Helper for formatting floats in base 16. More...
struct	to_element_t
class	memory_error
	Exception thrown when BulkAllocator-specific allocation errors happen. More...
class	BulkAllocator
	Aggressive allocator reserving a lot of memory in advance. More...
class	CollectionView
	Provides features of a collections, from begin and end iterators. More...
class	ComputePi
	Computes pi (but it does not make it available) More...
class	CountersMap
	Map storing counters in a compact way. More...
struct	SameAsDataTag
	Type for default tag in FindManyInChainP constructors. More...
class	FindManyInChainP
	Query object collecting a list of associated objects. More...
struct	has_const_iterator
class	Identity
	Functor returning the object specified as argument. More...
class	PairSecond
class	deep_const_fwd_iterator_nested
	Internal helper class: actual implementation of nested iterator. More...
class	ServicePackTest
	Test module for ServicePack.h utilities depending on art farmework. More...
class	const_value_box
	Little class storing a value. More...
class	value_const_iterator
	A constant iterator returning always the same value. More...
class	range_t
	A range (interval) of integers. More...
class	sparse_vector
	A sparse vector. More...

Typedefs
template<typename... Services>
using	providersFrom_t = lar::ProviderPack< typename Services::provider_type...>
	Type of a provider pack with a provider from each of the Services. More...
template<typename... Services>
using	ProviderPackFromServices = lar::ProviderPack< typename Services::provider_type...>
	Type of provider pack with providers from all specified Services. More...
template<typename BeginIter , typename EndIter = BeginIter>
using	RangeAsCollection_t = decltype(makeCollectionView(std::declval< BeginIter >(), std::declval< EndIter >()))
	Type of collection view owning the two range boundary iterators. More...
template<typename CITER , typename INNERCONTEXTRACT = Identity<typename CITER::value_type>>
using	double_fwd_const_iterator = deep_const_fwd_iterator_nested< CITER, INNERCONTEXTRACT >

Functions
template<typename T >
T::provider_type const *	providerFrom ()
	Returns a constant pointer to the provider of specified service. More...
template<typename... Services>
auto	providersFrom ()
	Returns a lar::ProviderPack with providers from all services. More...
template<typename... Providers>
ProviderPack< Providers...>	makeProviderPack (Providers const *...providers)
	Function to create a ProviderPack from the function arguments. More...
template<typename... PackProviders, typename... MoreProviders>
ProviderPack< PackProviders..., MoreProviders...>	expandProviderPack (ProviderPack< PackProviders...> const &pack, MoreProviders const *...providers)
	Function to create a ProviderPack by adding to another. More...
std::set< std::string > const &	IgnorableProviderConfigKeys ()
	Returns a list of configuration keys that providers should ignore. More...
template<typename... Services>
ProviderPackFromServices < Services...>	extractProviders ()
	Returns a provider pack with providers from specified services. More...
template<typename Range >
CollectionView< Range > const &	wrapCollectionIntoView (Range const &c)
	Returns the specified container, wrapped in the view. More...
template<typename BeginIter , typename EndIter >
auto	makeCollectionView (BeginIter const &b, EndIter const &e)
	Creates a CollectionView from the specified iterators. More...
constexpr bool	IsPowerOf2 (unsigned long long int v)
	Returns true if the argument is a power of 2. More...
constexpr int	LowestSetBit (unsigned long long int v)
	Returns the position of the first set bit (0 for LSB) More...
template<typename T >
value_const_iterator< T >	operator+ (typename value_const_iterator< T >::difference_type ofs, value_const_iterator< T > &iter)
	Returns an iterator pointing ahead of this one by the specified steps. More...

Variables
constexpr to_element_t	to_element
constexpr SameAsDataTag	SameAsData
	Value for default tag in FindManyInChainP constructors. More...

Detailed Description

LArSoft-specific namespace.

LArSoft libraries.

LArSoft namespace.

Namespace for generic LArSoft-related utilities.

Functor to dereference an object if the object is a pointer.

Bug:

BulkAllocator.h is currently broken; see issue #19494.

Author

Gianluca Petrillo (petri.nosp@m.llo@.nosp@m.fnal..nosp@m.gov)

Date

January 23rd, 2015LArSoft namespace

framework libraries

Typedef Documentation

template<typename CITER , typename INNERCONTEXTRACT = Identity<typename CITER::value_type>>

using lar::double_fwd_const_iterator = typedef deep_const_fwd_iterator_nested<CITER, INNERCONTEXTRACT>

Deep iterator

Todo:

write documentation about how to use it

Definition at line 77 of file NestedIterator.h.

template<typename... Services>

using lar::ProviderPackFromServices = typedef lar::ProviderPack<typename Services::provider_type...>

Type of provider pack with providers from all specified Services.

Definition at line 27 of file ServicePack.h.

template<typename... Services>

using lar::providersFrom_t = typedef lar::ProviderPack<typename Services::provider_type...>

Type of a provider pack with a provider from each of the Services.

---

Template Parameters

Services

the list of services to extract the provider type of

Example of usage in a art service class declaration:

using needed_providers_t = lar::providersFrom_t
  <geo::Geometry, detinfo::LArPropertiesService>;

Definition at line 142 of file ServiceUtil.h.

template<typename BeginIter , typename EndIter = BeginIter>

using lar::RangeAsCollection_t = typedef decltype (makeCollectionView(std::declval<BeginIter>(), std::declval<EndIter>()))

Type of collection view owning the two range boundary iterators.

Definition at line 440 of file CollectionView.h.

Function Documentation

template<typename... PackProviders, typename... MoreProviders>

ProviderPack<PackProviders..., MoreProviders...> lar::expandProviderPack	(	ProviderPack< PackProviders...> const &	pack,
		MoreProviders const *...	providers
	)

Function to create a ProviderPack by adding to another.

Template Parameters

PackProviders	types of the providers in the original parameter pack
MoreProviders	types of the providers to be added

Parameters

pack	parameter pack with the first providers
providers	constant pointers to the other providers to be added

Returns

a ProviderPack object containing all the specified providers

This is an convenience function to reduce the typing needed to instantiate a ProviderPack. Use it like:

A a;
B b;
C c;
D d;
auto pack = makeProviderPack(&a, &d);
auto largerPack = expandProviderPack(pack, &c, &b);

creates a ProviderPack<A, D, C, B> including all the four objects.

Definition at line 297 of file ProviderPack.h.

    { return { pack, providers... }; }

template<typename... Services>

ProviderPackFromServices<Services...> lar::extractProviders

(

)

Returns a provider pack with providers from specified services.

Template Parameters

Services

the services to extract the providers from

Returns

a ProviderPack containing the current service providers

This convenience function automatically extracts all the service providers from a list of services. This is convenient if an algorithm or service accepts a provider pack for setup:

algo->Setup(extractProviders<
  detinfo::DetectorPropertiesService, detinfo::LArPropertiesService
  >());

Also note that the provider packs can rearrange their elements, so the call above should work just the same as:

algo->Setup(extractProviders<
  detinfo::LArPropertiesService, detinfo::DetectorPropertiesService
  >());

If a provider is needed in the setup argument that is not provided by any of the specified services, a compilation error will occur.

Definition at line 54 of file ServicePack.h.

    { return { lar::providerFrom<Services>()... }; }

std::set<std::string> const& lar::IgnorableProviderConfigKeys ( )

inline

Returns a list of configuration keys that providers should ignore.

---

Returns

a reference to a key list

This function may be used for parameter validation, like in:

fhicl::Table<Config> cfg { pset, lar::IgnorableProviderConfigKeys() };

where pset is a fhicl::ParameterSet. This will inform cfg that some keys can be unexpectedly present, or missing.

This implementation includes:

• art framework service keywords

Definition at line 35 of file ProviderUtil.h.

    {
      static std::set<std::string> const ignorable {
        "service_type",     // added by art: service name (possibly interface)
        "service_provider"  // art: service implementation name
        };
      return ignorable;
    } // IgnorableProviderConfigKeys()

constexpr bool lar::IsPowerOf2

(

unsigned long long int

v

)

Returns true if the argument is a power of 2.

Definition at line 25 of file CountersMap.h.

    { return v & 1? v == 1: IsPowerOf2(v >> 1); }

constexpr int lar::LowestSetBit ( unsigned long long int  v )

inline

Returns the position of the first set bit (0 for LSB)

Definition at line 413 of file CountersMap.h.

    { return (v == 0)? -1: details::LowestSetBitScaler(v, 0); }

template<typename BeginIter , typename EndIter >

auto lar::makeCollectionView	(	BeginIter const &	b,
		EndIter const &	e
	)

Creates a CollectionView from the specified iterators.

Definition at line 432 of file CollectionView.h.

    {
      return details::makeCollectionView(details::makeCollectionExtremes(b, e));
    }

template<typename... Providers>

ProviderPack<Providers...> lar::makeProviderPack

(

Providers const *...

providers

)

Function to create a ProviderPack from the function arguments.

Template Parameters

Providers

types of the providers in the parameter pack

Parameters

providers

constant pointers to the providers

Returns

a ProviderPack object containing all the specified providers

This is an convenience function to reduce the typing needed to instantiate a ProviderPack. Example:

A a;
B b;
auto pack = makeProviderPack(&a, &b);

creates a ProviderPack<A, B>.

Definition at line 272 of file ProviderPack.h.

    { return ProviderPack<Providers...>(providers...); }

template<typename T >

value_const_iterator<T> lar::operator+	(	typename value_const_iterator< T >::difference_type	ofs,
		value_const_iterator< T > &	iter
	)

Returns an iterator pointing ahead of this one by the specified steps.

Parameters

ofs	number of steps ahead
iter	base iterator

Definition at line 151 of file sparse_vector.h.

  { return { iter.value, iter.index + ofs }; }

template<typename T >

T::provider_type const* lar::providerFrom

(

)

Returns a constant pointer to the provider of specified service.

---

Template Parameters

T	type of the service

Returns

a constant pointer to the provider of specified service

Exceptions

art::Exception

(category art::errors::NotFound) if pointer is null

This function relies on the following service and provider interface:

• provider is not movable nor copyable
• service contains a type provider_type defined as the class of the service provider
• service contains a method "provider()" that returns a non-null pointer to a service provider; the service provider is owned and managed by the service, and the caller is not responsible of regulating the object lifetime, nor it should attempt to

Violations of the protocol yield compilation errors (in case non-compliance can be statically detected), or throw of exceptions.

Example of usage:

auto const* geom = lar::providerFrom<geo::Geometry>();

retrieves the service provider for LArSoft geometry. This requires the inclusion of "Geometry/Geometry.h" header, where the service is declared. Typically, both ServiceUtil.h and the header of the provider class are included in the service header.

Definition at line 77 of file ServiceUtil.h.

    {
      using Service_t = std::add_const_t<T>;
      using Provider_t = typename Service_t::provider_type;
      
      (void) details::ServiceRequirementsChecker<Service_t>();

      // retrieve the provider
      art::ServiceHandle<Service_t> h;
      Provider_t const* const pProvider { h->provider() };
      if (!pProvider) {
        throw art::Exception(art::errors::NotFound)
          << "ServiceHandle <" << cet::demangle_symbol(typeid(Service_t).name())
          << "> offered a null provider";
      }

      return pProvider;

    } // providerFrom()

template<typename... Services>

auto lar::providersFrom

(

)

Returns a lar::ProviderPack with providers from all services.

---

Template Parameters

Services

a list of service types

Returns

a lar::ProviderPack with providers from all specified services

Exceptions

art::Exception

as lar::providerFrom()

See Also

lar::providerFrom()

This function relies on lar::providerFrom() to extract providers from all the specified services. The parameter pack stores the providers in the same order as the services were specified, but this is not very relevant since provider packs can be implicitly converted in other provider packs with the same providers in a different order.

Example of usage:

prov->setup
  (lar::providersFrom<geo::Geometry, detinfo::LArPropertiesService>());

retrieves the service providers for LArSoft geometry and LArPropertiesService, and passes them as a provider pack to a setup() method, presumably from a algorithm or service provider that needs them. This requires the inclusion of "Geometry/Geometry.h" and "LArPropertiesService.h" headers, where the services are declared. Typically, both ServiceUtil.h and the header of the provider class are included in the service headers.

Definition at line 126 of file ServiceUtil.h.

    { return details::ProviderPackExtractor<Services...>::parameterPack(); }

template<typename Range >

CollectionView<Range> const& lar::wrapCollectionIntoView

(

Range const &

c

)

Returns the specified container, wrapped in the view.

Definition at line 425 of file CollectionView.h.

    { return reinterpret_cast<CollectionView<Range> const&>(c); }

Variable Documentation

constexpr SameAsDataTag lar::SameAsData

Value for default tag in FindManyInChainP constructors.

Definition at line 47 of file FindManyInChainP.h.

constexpr to_element_t lar::to_element

inline

Definition at line 24 of file ToElement.h.