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Editing: has_function.hpp
// (C) Copyright Edward Diener 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_FUNCTION_HPP) #define BOOST_TTI_HAS_FUNCTION_HPP #include <boost/config.hpp> #include <boost/function_types/property_tags.hpp> #include <boost/mpl/vector.hpp> #include <boost/preprocessor/cat.hpp> #include <boost/tti/detail/dfunction.hpp> #include <boost/tti/gen/has_function_gen.hpp> /* The succeeding comments in this file are in doxygen format. */ /** \file */ /// A macro which expands to a metafunction which tests whether a member function or a static member function with a particular name and signature exists. /** BOOST_TTI_TRAIT_HAS_FUNCTION is a macro which expands to a metafunction. The metafunction tests whether a member function or a static member function with a particular name and signature exists. The macro takes the form of BOOST_TTI_TRAIT_HAS_FUNCTION(trait,name) where trait = the name of the metafunction <br/> name = the name of the inner member. BOOST_TTI_TRAIT_HAS_FUNCTION generates a metafunction called "trait" where 'trait' is the macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_R,class BOOST_TTI_TP_FS,class BOOST_TTI_TP_TAG> struct trait { static const value = unspecified; typedef mpl::bool_<true-or-false> type; }; The metafunction types and return: BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'. The enclosing type can be a class, struct, or union. BOOST_TTI_TP_R = the return type of the function BOOST_TTI_TP_FS = (optional) the parameters of the function as a boost::mpl forward sequence if function parameters are not empty. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function if the need for a tag exists. returns = 'value' is true if the 'name' exists, with the appropriate static member function type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_TRAIT_HAS_FUNCTION(trait,name) \ BOOST_TTI_DETAIL_TRAIT_HAS_FUNCTION(trait,name) \ template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_R,class BOOST_TTI_TP_FS = boost::mpl::vector<>,class BOOST_TTI_TP_TAG = boost::function_types::null_tag> \ struct trait \ { \ typedef typename \ BOOST_PP_CAT(trait,_detail_hf)<BOOST_TTI_TP_T,BOOST_TTI_TP_R,BOOST_TTI_TP_FS,BOOST_TTI_TP_TAG>::type type; \ BOOST_STATIC_CONSTANT(bool,value=type::value); \ }; \ /**/ /// A macro which expands to a metafunction which tests whether a member function or a static member function with a particular name and signature exists. /** BOOST_TTI_HAS_FUNCTION is a macro which expands to a metafunction. The metafunction tests whether a member function or a static member function with a particular name and signature exists. The macro takes the form of BOOST_TTI_HAS_FUNCTION(name) where name = the name of the inner member. BOOST_TTI_HAS_FUNCTION generates a metafunction called "has_function_name" where 'name' is the macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_R,class BOOST_TTI_TP_FS,class BOOST_TTI_TP_TAG> struct has_function_'name' { static const value = unspecified; typedef mpl::bool_<true-or-false> type; }; The metafunction types and return: BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'. The enclosing type can be a class, struct, or union. BOOST_TTI_TP_R = the return type of the function BOOST_TTI_TP_FS = (optional) the parameters of the function as a boost::mpl forward sequence if function parameters are not empty. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function if the need for a tag exists. returns = 'value' is true if the 'name' exists, with the appropriate function type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_HAS_FUNCTION(name) \ BOOST_TTI_TRAIT_HAS_FUNCTION \ ( \ BOOST_TTI_HAS_FUNCTION_GEN(name), \ name \ ) \ /**/ #endif // BOOST_TTI_HAS_FUNCTION_HPP
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