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Diffstat (limited to 'boost/convert/detail/is_fun.hpp')
-rw-r--r-- | boost/convert/detail/is_fun.hpp | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/boost/convert/detail/is_fun.hpp b/boost/convert/detail/is_fun.hpp new file mode 100644 index 0000000000..5e1eae2ca6 --- /dev/null +++ b/boost/convert/detail/is_fun.hpp @@ -0,0 +1,61 @@ +// Copyright (c) 2009-2014 Vladimir Batov. +// Use, modification and distribution are subject to the Boost Software License, +// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt. + +#ifndef BOOST_CONVERT_IS_FUNCTION_HPP +#define BOOST_CONVERT_IS_FUNCTION_HPP + +#include <boost/convert/detail/forward.hpp> +#include <boost/convert/detail/has_member.hpp> +#include <boost/utility/enable_if.hpp> +#include <boost/type_traits.hpp> +#include <boost/function_types/is_function_pointer.hpp> +#include <boost/function_types/function_arity.hpp> +#include <boost/function_types/result_type.hpp> + +namespace boost { namespace cnv +{ + typedef ::boost::type_traits::yes_type yes_type; + typedef ::boost::type_traits:: no_type no_type; + + template <bool has_operator, typename Functor, typename TypeOut> + struct check_functor { BOOST_STATIC_CONSTANT(bool, value = false); }; + + template<typename Func, typename TypeOut, class Enable =void> + struct is_fun { BOOST_STATIC_CONSTANT(bool, value = false); }; + + template <typename Functor, typename TypeOut> + struct check_functor<true, Functor, TypeOut> + { + static yes_type test (TypeOut const&); + static no_type test (...); + + static const bool value = sizeof(yes_type) == sizeof(test(((Functor*) 0)->operator()())); + }; + + template<typename Functor, typename TypeOut> + struct is_fun<Functor, TypeOut, + typename enable_if_c<is_class<Functor>::value && !is_convertible<Functor, TypeOut>::value, void>::type> + { + BOOST_DECLARE_HAS_MEMBER(has_funop, operator()); + + BOOST_STATIC_CONSTANT(bool, value = (check_functor<has_funop<Functor>::value, Functor, TypeOut>::value)); + }; + + template<typename Function, typename TypeOut> + struct is_fun<Function, TypeOut, + typename enable_if_c< + function_types::is_function_pointer<Function>::value && + function_types::function_arity<Function>::value == 0 && + !is_same<Function, TypeOut>::value, + void>::type> + { + typedef TypeOut out_type; + typedef typename function_types::result_type<Function>::type func_out_type; + + BOOST_STATIC_CONSTANT(bool, value = (is_convertible<func_out_type, out_type>::value)); + }; +}} + +#endif // BOOST_CONVERT_IS_FUNCTION_HPP + |