...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
BOOST_FUSION_ADAPT_ASSOC_TPL_STRUCT is a macro that can be used to generate all the necessary boilerplate to make an arbitrary template struct a model of Random Access Sequence and Associative Sequence.
BOOST_FUSION_ADAPT_ASSOC_TPL_STRUCT( (template_param0)(template_param1)..., (struct_name) (specialization_param0)(specialization_param1)..., ([member_type0,] member_name0, key_type0) ([member_type1,] member_name1, key_type1) ... )
The above macro generates the necessary code to adapt struct_name
or an arbitrary specialization of struct_name
as a model of Random
Access Sequence and Associative
Sequence. The sequence (template_param0)(template_param1)...
declares the names of the template type parameters used. The sequence (specialization_param0)(specialization_param1)...
declares the template parameters of the
actual specialization of struct_name
that is adapted as a fusion sequence. The sequence of ([member_typeN,]
member_nameN,
key_typeN)
tuples declares the type, name and key type of each of the struct members
that are part of the sequence.
When member_typeN is omitted or set to auto, the type is infered with Boost.TypeOf.
The macro should be used at global scope, and struct_name
should be the fully namespace qualified name of the struct to be adapted.
#include <boost/fusion/adapted/struct/adapt_assoc_struct.hpp> #include <boost/fusion/include/adapt_assoc_struct.hpp>
namespace demo { template<typename Name, typename Age> struct employee { Name name; Age age; }; } namespace keys { struct name; struct age; } // Any instantiated demo::employee is now a Fusion sequence. // It is also an associative sequence with // keys keys::name and keys::age present. BOOST_FUSION_ADAPT_ASSOC_TPL_STRUCT( (Name)(Age), (demo::employee) (Name)(Age), (name, keys::name) (age, keys::age)) // Without BOOST_PP_VARIADICS support : BOOST_FUSION_ADAPT_ASSOC_TPL_STRUCT( (Name)(Age), (demo::employee) (Name)(Age), (Name, name, keys::name) (Age, age, keys::age))