1 | // Copyright (c) 2009-2014 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_FUNCTION_HPP |
6 | #define BOOST_CONVERT_IS_FUNCTION_HPP |
7 | |
8 | #include <boost/convert/detail/forward.hpp> |
9 | #include <boost/convert/detail/has_member.hpp> |
10 | #include <boost/utility/enable_if.hpp> |
11 | #include <boost/type_traits.hpp> |
12 | #include <boost/function_types/is_function_pointer.hpp> |
13 | #include <boost/function_types/function_arity.hpp> |
14 | #include <boost/function_types/result_type.hpp> |
15 | |
16 | namespace boost { namespace cnv |
17 | { |
18 | typedef ::boost::type_traits::yes_type yes_type; |
19 | typedef ::boost::type_traits:: no_type no_type; |
20 | |
21 | template <bool has_operator, typename Functor, typename TypeOut> |
22 | struct check_functor { BOOST_STATIC_CONSTANT(bool, value = false); }; |
23 | |
24 | template<typename Func, typename TypeOut, class Enable =void> |
25 | struct is_fun { BOOST_STATIC_CONSTANT(bool, value = false); }; |
26 | |
27 | template <typename Functor, typename TypeOut> |
28 | struct check_functor<true, Functor, TypeOut> |
29 | { |
30 | static yes_type test (TypeOut const&); |
31 | static no_type test (...); |
32 | |
33 | static const bool value = sizeof(yes_type) == sizeof(test(((Functor*) 0)->operator()())); |
34 | }; |
35 | |
36 | template<typename Functor, typename TypeOut> |
37 | struct is_fun<Functor, TypeOut, |
38 | typename enable_if_c<is_class<Functor>::value && !is_convertible<Functor, TypeOut>::value, void>::type> |
39 | { |
40 | BOOST_DECLARE_HAS_MEMBER(has_funop, operator()); |
41 | |
42 | BOOST_STATIC_CONSTANT(bool, value = (check_functor<has_funop<Functor>::value, Functor, TypeOut>::value)); |
43 | }; |
44 | |
45 | template<typename Function, typename TypeOut> |
46 | struct is_fun<Function, TypeOut, |
47 | typename enable_if_c< |
48 | function_types::is_function_pointer<Function>::value && |
49 | function_types::function_arity<Function>::value == 0 && |
50 | !is_same<Function, TypeOut>::value, |
51 | void>::type> |
52 | { |
53 | typedef TypeOut out_type; |
54 | typedef typename function_types::result_type<Function>::type func_out_type; |
55 | |
56 | BOOST_STATIC_CONSTANT(bool, value = (is_convertible<func_out_type, out_type>::value)); |
57 | }; |
58 | }} |
59 | |
60 | #endif // BOOST_CONVERT_IS_FUNCTION_HPP |
61 | |
62 | |