1 // Copyright (c) 2009-2016 Vladimir Batov. 2 // Use, modification and distribution are subject to the Boost Software License, 3 // Version 1.0. See http://www.boost.org/LICENSE_1_0.txt. 4 5 #ifndef BOOST_CONVERT_IS_CONVERTER_HPP 6 #define BOOST_CONVERT_IS_CONVERTER_HPP 7 8 #include <boost/convert/detail/config.hpp> 9 #include <boost/convert/detail/is_callable.hpp> 10 #include <boost/utility/enable_if.hpp> 11 #include <boost/type_traits.hpp> 12 #include <boost/ref.hpp> 13 14 namespace boost { namespace cnv 15 { 16 template<typename, typename, typename, typename =void> 17 struct is_cnv { BOOST_STATIC_CONSTANT(bool, value = false); }; 18 19 template<typename Class, typename TypeIn, typename TypeOut> 20 struct is_cnv<Class, TypeIn, TypeOut, typename enable_if<is_class<Class>, void>::type> 21 { 22 typedef typename ::boost::unwrap_reference<Class>::type class_type; 23 typedef void signature_type(TypeIn const&, optional<TypeOut>&); 24 25 BOOST_DECLARE_IS_CALLABLE(is_callable, operator()); 26 27 BOOST_STATIC_CONSTANT(bool, value = (is_callable<class_type, signature_type>::value)); 28 }; 29 30 template<typename Function, typename TypeIn, typename TypeOut> 31 struct is_cnv<Function, TypeIn, TypeOut, 32 typename enable_if_c<is_function<Function>::value && function_types::function_arity<Function>::value == 2, 33 void>::type> 34 { 35 typedef TypeIn in_type; 36 typedef optional<TypeOut>& out_type; 37 typedef typename function_traits<Function>::arg1_type func_in_type; 38 typedef typename function_traits<Function>::arg2_type func_out_type; 39 40 BOOST_STATIC_CONSTANT(bool, in_good = (is_convertible<in_type, func_in_type>::value)); 41 BOOST_STATIC_CONSTANT(bool, out_good = (is_same<out_type, func_out_type>::value)); 42 BOOST_STATIC_CONSTANT(bool, value = (in_good && out_good)); 43 }; 44 }} 45 46 #endif // BOOST_CONVERT_IS_CONVERTER_HPP 47 48