boost/tti/has_function_template.hpp
// (C) Copyright Edward Diener 2019 // 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_FUNCTION_TEMPLATE_HPP) #define BOOST_TTI_FUNCTION_TEMPLATE_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/gen/namespace_gen.hpp> #include <boost/tti/gen/has_function_template_gen.hpp> #include <boost/tti/detail/dfunction_template.hpp> #if BOOST_PP_VARIADICS #include <boost/tti/detail/dmacro_fun_template.hpp> /* The succeeding comments in this file are in doxygen format. */ /** \file */ /// A macro which expands to a metafunction which tests whether an inner member function template or static member function template with a particular name exists. /** BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE is a macro which expands to a metafunction. The metafunction tests whether an inner member function template or static member function template with a particular name exists. The macro takes the form of BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,...) where trait = the name of the metafunction <br/> name = inner member function template or static member function template name <br/> ... = variadic parameters. The variadic parameter(s) are either: A sequence of valid instantiations for the static member function template parameters ie. 'int,long,double' etc. or A single variadic parameter which is a Boost PP array whose elements are a sequence of valid instantiations for the static member function template parameters ie. '(3,(int,long,double))' etc. This form is allowed in order to be compatible with using the non-variadic form of this macro. BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE generates a metafunction called "trait" where 'trait' is the first macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_R,class BOOST_TTI_FS,class BOOST_TTI_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 template in a single instantiation of the function template BOOST_TTI_TP_FS = (optional) the parameters of the function template as a boost::mpl forward sequence if the function template parameters are not empty. These parameters are a single instantiation of the function template. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function template if a tag is needed. returns = 'value' is true if the 'name' exists, with the appropriate member function template or static member function template type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,...) \ BOOST_TTI_DETAIL_TRAIT_HAS_FUNCTION_TEMPLATE \ ( \ trait, \ name, \ BOOST_TTI_DETAIL_FUN_TEMPLATE_VARIADIC_TO_ARRAY(__VA_ARGS__) \ ) \ 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_hft)<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 an inner member function template or static member function template with a particular name exists. /** BOOST_TTI__HAS_FUNCTION_TEMPLATE is a macro which expands to a metafunction. The metafunction tests whether an inner member function template or static member function template with a particular name exists. The macro takes the form of BOOST_TTI_HAS_FUNCTION_TEMPLATE(name,...) where name = inner member function template or static member function template name <br/> ... = variadic parameters. The variadic parameter(s) are either: A sequence of valid instantiations for the static member function template parameters ie. 'int,long,double' etc. or A single variadic parameter which is a Boost PP array whose elements are a sequence of valid instantiations for the static member function template parameters ie. '(3,(int,long,double))' etc. This form is allowed in order to be compatible with using the non-variadic form of this macro. BOOST_TTI_HAS_FUNCTION_TEMPLATE generates a metafunction called "has_function_template_'name'" where 'name' is the first macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_R,class BOOST_TTI_FS,class BOOST_TTI_TAG> struct has_function_template_'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 template in a single instantiation of the function template BOOST_TTI_TP_FS = (optional) the parameters of the function template as a boost::mpl forward sequence if the function template parameters are not empty. These parameters are a single instantiation of the function template. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function template if a tag is needed. returns = 'value' is true if the 'name' exists, with the appropriate member function template or static member function template type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_HAS_FUNCTION_TEMPLATE(name,...) \ BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE \ ( \ BOOST_TTI_HAS_FUNCTION_TEMPLATE_GEN(name), \ name, \ __VA_ARGS__ \ ) \ /**/ #else // !BOOST_PP_VARIADICS /* The succeeding comments in this file are in doxygen format. */ /** \file */ /// A macro which expands to a metafunction which tests whether an inner member function template or static member function template with a particular name exists. /** BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE is a macro which expands to a metafunction. The metafunction tests whether an inner member function template or static member function template with a particular name exists. The macro takes the form of BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,pparray) where trait = the name of the metafunction <br/> name = inner member function template or static member function template name <br/> pparray = a Boost PP array whose elements are a sequence of valid instantiations for the static member function template parameters ie. '(3,(int,long,double))' etc. BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE generates a metafunction called "trait" where 'trait' is the first macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_R,class BOOST_TTI_FS,class BOOST_TTI_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 template in a single instantiation of the function template BOOST_TTI_TP_FS = (optional) the parameters of the function template as a boost::mpl forward sequence if the function template parameters are not empty. These parameters are a single instantiation of the function template. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function template if a tag is needed. returns = 'value' is true if the 'name' exists, with the appropriate member function template or static member function template type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,pparray) \ BOOST_TTI_DETAIL_TRAIT_HAS_FUNCTION_TEMPLATE(trait,name,pparray) \ 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_hft)<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 an inner member function template or static member function template with a particular name exists. /** BOOST_TTI_HAS_FUNCTION_TEMPLATE is a macro which expands to a metafunction. The metafunction tests whether an inner member function template or static member function template with a particular name exists. The macro takes the form of BOOST_TTI_HAS_FUNCTION_TEMPLATE(name,pparray) where name = inner member function template or static member function template name <br/> pparray = a Boost PP array whose elements are a sequence of valid instantiations for the static member function template parameters ie. '(3,(int,long,double))' etc. BOOST_TTI_HAS_FUNCTION_TEMPLATE generates a metafunction called "has_function_template_'name'" where 'name' is the first macro parameter. @code template<class BOOST_TTI_TP_T,class BOOST_TTI_R,class BOOST_TTI_FS,class BOOST_TTI_TAG> struct has_function_template_'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 template in a single instantiation of the function template BOOST_TTI_TP_FS = (optional) the parameters of the function template as a boost::mpl forward sequence if the function template parameters are not empty. These parameters are a single instantiation of the function template. BOOST_TTI_TP_TAG = (optional) a boost::function_types tag to apply to the function template if a tag is needed. returns = 'value' is true if the 'name' exists, with the appropriate member function template or static member function template type, otherwise 'value' is false. @endcode */ #define BOOST_TTI_HAS_FUNCTION_TEMPLATE(name,pparray) \ BOOST_TTI_TRAIT_HAS_FUNCTION_TEMPLATE \ ( \ BOOST_TTI_HAS_FUNCTION_TEMPLATE_GEN(name), \ name, \ pparray \ ) \ /**/ #endif // BOOST_PP_VARIADICS #endif // BOOST_TTI_FUNCTION_TEMPLATE_HPP