ceph/src/boost/boost/mp11/detail/mp_map_find.hpp

   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
  13 namespace boost
  14 {
  15 namespace mp11
  16 {
  17
  18 // mp_map_find
  19 namespace detail
  20 {
  21
  22 template<class M, class K> struct mp_map_find_impl;
  23
  24 template<template<class...> class M, class... T, class K> struct mp_map_find_impl<M<T...>, K>
  25 {
  26     using U = mp_inherit<mp_identity<T>...>;
  27
  28     template<template<class...> class L, class... U> static mp_identity<L<K, U...>> f( mp_identity<L<K, U...>>* );
  29     static mp_identity<void> f( ... );
  30
  31     using V = decltype( f((U*)0) );
  32
  33     using type = typename V::type;
  34 };
  35
  36 } // namespace detail
  37
  38 template<class M, class K> using mp_map_find = typename detail::mp_map_find_impl<M, K>::type;
  39
  40 } // namespace mp11
  41 } // namespace boost
  42
  43 #endif // #ifndef BOOST_MP11_DETAIL_MP_MAP_FIND_HPP_INCLUDED