1 | #ifndef BOOST_MP11_DETAIL_MP_MAP_FIND_HPP_INCLUDED |
2 | #define BOOST_MP11_DETAIL_MP_MAP_FIND_HPP_INCLUDED |
3 | |
4 | // Copyright 2015 Peter Dimov. |
5 | // |
6 | // Distributed under the Boost Software License, Version 1.0. |
7 | // |
8 | // See accompanying file LICENSE_1_0.txt or copy at |
9 | // http://www.boost.org/LICENSE_1_0.txt |
10 | |
11 | #include <boost/mp11/utility.hpp> |
12 | #include <boost/mp11/detail/config.hpp> |
13 | |
14 | #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1930 ) |
15 | |
16 | // not exactly good practice, but... |
17 | namespace std |
18 | { |
19 | template<class... _Types> class tuple; |
20 | } |
21 | |
22 | #endif |
23 | |
24 | namespace boost |
25 | { |
26 | namespace mp11 |
27 | { |
28 | |
29 | // mp_map_find |
30 | namespace detail |
31 | { |
32 | |
33 | #if !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1930 ) |
34 | |
35 | template<class T> using mpmf_wrap = mp_identity<T>; |
36 | template<class T> using mpmf_unwrap = typename T::type; |
37 | |
38 | #else |
39 | |
40 | template<class... T> struct mpmf_tuple {}; |
41 | |
42 | template<class T> struct mpmf_wrap_impl |
43 | { |
44 | using type = mp_identity<T>; |
45 | }; |
46 | |
47 | template<class... T> struct mpmf_wrap_impl< std::tuple<T...> > |
48 | { |
49 | using type = mp_identity< mpmf_tuple<T...> >; |
50 | }; |
51 | |
52 | template<class T> using mpmf_wrap = typename mpmf_wrap_impl<T>::type; |
53 | |
54 | template<class T> struct mpmf_unwrap_impl |
55 | { |
56 | using type = typename T::type; |
57 | }; |
58 | |
59 | template<class... T> struct mpmf_unwrap_impl< mp_identity< mpmf_tuple<T...> > > |
60 | { |
61 | using type = std::tuple<T...>; |
62 | }; |
63 | |
64 | template<class T> using mpmf_unwrap = typename mpmf_unwrap_impl<T>::type; |
65 | |
66 | #endif // #if !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1930 ) |
67 | |
68 | template<class M, class K> struct mp_map_find_impl; |
69 | |
70 | template<template<class...> class M, class... T, class K> struct mp_map_find_impl<M<T...>, K> |
71 | { |
72 | using U = mp_inherit<mpmf_wrap<T>...>; |
73 | |
74 | template<template<class...> class L, class... U> static mp_identity<L<K, U...>> f( mp_identity<L<K, U...>>* ); |
75 | static mp_identity<void> f( ... ); |
76 | |
77 | using type = mpmf_unwrap< decltype( f( static_cast<U*>(0) ) ) >; |
78 | }; |
79 | |
80 | } // namespace detail |
81 | |
82 | template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type; |
83 | |
84 | } // namespace mp11 |
85 | } // namespace boost |
86 | |
87 | #endif // #ifndef BOOST_MP11_DETAIL_MP_MAP_FIND_HPP_INCLUDED |
88 | |