// (C) Copyright Edward Diener 2011,2012,2013 // Use, modification and distribution are subject to the Boost Software License, // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt). #if !defined(BOOST_TTI_HAS_MEMBER_DATA_HPP) #define BOOST_TTI_HAS_MEMBER_DATA_HPP #include #include #include #include #include /* The succeeding comments in this file are in doxygen format. */ /** \file */ /// A macro which expands to a metafunction which tests whether member data with a particular name and type exists. /** BOOST_TTI_TRAIT_HAS_MEMBER_DATA is a macro which expands to a metafunction. The metafunction tests whether member data with a particular name and type exists. The macro takes the form of BOOST_TTI_TRAIT_HAS_MEMBER_DATA(trait,name) where trait = the name of the metafunction.
name = the name of the inner member data. BOOST_TTI_TRAIT_HAS_MEMBER_DATA generates a metafunction called "trait" where 'trait' is the macro parameter. @code template struct trait { static const value = unspecified; typedef mpl::bool_ type; }; The metafunction types and return: BOOST_TTI_TP_ET = the enclosing type in which to look for our 'name' The enclosing type can be a class, struct, or union. OR The type of the member data in the form of a pointer to member data. BOOST_TTI_TP_TYPE = (optional) The type of the member data if the first parameter is the enclosing type. returns = 'value' is true if the 'name' exists, with the correct data type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_TRAIT_HAS_MEMBER_DATA(trait,name) \ BOOST_TTI_DETAIL_TRAIT_HAS_MEMBER_DATA(trait,name) \ template \ struct trait \ { \ typedef typename \ BOOST_PP_CAT(trait,_detail_hmd) \ < \ BOOST_TTI_TP_ET, \ BOOST_TTI_TP_TYPE \ >::type type; \ BOOST_STATIC_CONSTANT(bool,value=type::value); \ }; \ /**/ /// A macro which expands to a metafunction which tests whether a member data with a particular name and type exists. /** BOOST_TTI_HAS_MEMBER_DATA is a macro which expands to a metafunction. The metafunction tests whether member data with a particular name and type exists. The macro takes the form of BOOST_TTI_HAS_MEMBER_DATA(name) where name = the name of the inner member. BOOST_TTI_HAS_MEMBER_DATA generates a metafunction called "has_member_data_name" where 'name' is the macro parameter. @code template struct has_member_data_'name' { static const value = unspecified; typedef mpl::bool_ type; }; The metafunction types and return: BOOST_TTI_TP_ET = the enclosing type in which to look for our 'name'. The enclosing type can be a class, struct, or union. OR The type of the member data in the form of a pointer to member data. BOOST_TTI_TP_TYPE = (optional) The type of the member data if the first parameter is the enclosing type. returns = 'value' is true if the 'name' exists, with the correct data type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_HAS_MEMBER_DATA(name) \ BOOST_TTI_TRAIT_HAS_MEMBER_DATA \ ( \ BOOST_TTI_HAS_MEMBER_DATA_GEN(name), \ name \ ) \ /**/ #endif // BOOST_TTI_HAS_MEMBER_DATA_HPP