LArSoft  v09_90_00
Liquid Argon Software toolkit - https://larsoft.org/

Simple traits for container classes.Trait classes describing a type have a type member defined after that type. They are also available as template types, in the fashion of C++14. More...

Classes

struct  util::collection_value_type< Coll >
 Trait of value contained in the template collection Coll. More...
 
struct  util::collection_value_access_type< Coll >
 Trait of type obtained by access to element of collection Coll. More...
 
struct  util::collection_value_constant_access_type< Coll >
 Trait of type obtained by constant access to element of collection Coll. More...
 
struct  util::collection_reference_type< Coll >
 Trait of a type that can be used to reference the collection Coll. More...
 
struct  util::collection_from_reference_type< CollRef >
 Trait with the type of collection referenced by collRef. More...
 

Typedefs

template<typename Coll >
using util::collection_value_t = typename collection_value_type< Coll >::type
 Type contained in the collection Coll. More...
 
template<typename Coll >
using util::collection_value_access_t = typename collection_value_access_type< Coll >::type
 Type obtained by constant access to element of collection Coll. More...
 
template<typename Coll >
using util::collection_value_constant_access_t = typename collection_value_constant_access_type< Coll >::type
 Type obtained by constant access to element of collection Coll. More...
 
template<typename Coll >
using util::collection_reference_t = typename collection_reference_type< Coll >::type
 The type contained in util::collection_reference_type trait. More...
 
template<typename Cont >
using util::collection_from_reference_t = typename collection_from_reference_type< Cont >::type
 Type contained in util::collection_from_reference_type trait. More...
 

Functions

template<typename Coll >
auto util::make_collection_reference (Coll &&coll)
 Returns an object referencing to the data contained in coll. More...
 
template<typename CollRef >
decltype(auto) util::collection_from_reference (CollRef &collRef)
 Returns the object referenced by collRef as a C++ reference. More...
 

Detailed Description

Simple traits for container classes.

Trait classes describing a type have a type member defined after that type. They are also available as template types, in the fashion of C++14.

Trait classes describing a value have a value member (static, constexpr) defined with that value. They are also available as template constants, in the fashion of C++17.

Container value traits

Container classes mimicking the C++ STL interface provide a value_type type detailing the contained object. This is generalised in the util::collection_value_type trait, which can be specialised for containers which do not support that.

Two additional traits are provided, which describe the type obtained by accessing an element of the container. This is a close relative of util::collection_value_type, but it may be decorated by l-value reference or constantness depending on the container. The two traits represent access one to a container that is mutable, the other to one that is constant.

Typedef Documentation

template<typename Cont >
using util::collection_from_reference_t = typedef typename collection_from_reference_type<Cont>::type

Type contained in util::collection_from_reference_type trait.

Definition at line 139 of file ContainerMeta.h.

template<typename Coll >
using util::collection_reference_t = typedef typename collection_reference_type<Coll>::type

The type contained in util::collection_reference_type trait.

Definition at line 103 of file ContainerMeta.h.

template<typename Coll >
using util::collection_value_access_t = typedef typename collection_value_access_type<Coll>::type

Type obtained by constant access to element of collection Coll.

Definition at line 71 of file ContainerMeta.h.

template<typename Coll >
using util::collection_value_constant_access_t = typedef typename collection_value_constant_access_type<Coll>::type

Type obtained by constant access to element of collection Coll.

Definition at line 81 of file ContainerMeta.h.

template<typename Coll >
using util::collection_value_t = typedef typename collection_value_type<Coll>::type

Type contained in the collection Coll.

Definition at line 62 of file ContainerMeta.h.

Function Documentation

template<typename CollRef >
decltype(auto) util::collection_from_reference ( CollRef &  collRef)

Returns the object referenced by collRef as a C++ reference.

Template Parameters
CollReftype of collection of the data
Parameters
collRefcollection of the data to be referenced to
Returns
a reference to the object referenced by collRef
See also
util::make_collection_reference()

The return value is a direct reference to the unwrapped container collRef. For example, a collRef of type std::reference_wrapper will result in a C reference of the wrapped container, while a C pointer is left unchanged and a std::unique_ptr object is turned into the equivalent pointer to its elements.

Definition at line 385 of file ContainerMeta.h.

References util::details::collection_from_reference_impl< CollRef, typename >::get().

Referenced by util::details::ContainerStorageBase< Mapping >::container(), and util::MappedContainer< Cont, Mapping >::minimal_size().

386  {
388  }
decltype(auto) get(T &&obj)
ADL-aware version of std::to_string.
Definition: StdUtils.h:120
template<typename Coll >
auto util::make_collection_reference ( Coll &&  coll)

Returns an object referencing to the data contained in coll.

Template Parameters
Colltype of collection of the data
Returns
an object referencing to the data contained in coll
See also
util::collection_from_reference()

The criteria, as well as the type of the returned object, are similar to util::collection_reference_type. Therefore, for example a C pointer is returned unchanged, while a std::vector is returned wrapped into a std::reference_wrapper. A std::unique_ptr is returned as bare pointer, given that the returned object does not own the data.

Definition at line 373 of file ContainerMeta.h.

References art::InputSourceFactory::make().

Referenced by phot::IPhotonMappingTransformations::applyOpDetMapping().

374  {
375  return details::make_collection_reference_impl<std::remove_reference_t<Coll>>::make(coll);
376  }
std::unique_ptr< InputSource > make(fhicl::ParameterSet const &conf, InputSourceDescription &desc)