ceph/src/boost/boost/hana/concept/hashable.hpp

   1 /*!
   2 @file
   3 Defines `boost::hana::Hashable`.
   4
   5 @copyright Louis Dionne 2016
   6 @copyright Jason Rice 2016
   7 Distributed under the Boost Software License, Version 1.0.
   8 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   9  */
  10
  11 #ifndef BOOST_HANA_CONCEPT_HASHABLE_HPP
  12 #define BOOST_HANA_CONCEPT_HASHABLE_HPP
  13
  14 #include <boost/hana/fwd/concept/hashable.hpp>
  15
  16 #include <boost/hana/config.hpp>
  17 #include <boost/hana/core/default.hpp>
  18 #include <boost/hana/core/tag_of.hpp>
  19 #include <boost/hana/detail/integral_constant.hpp>
  20 #include <boost/hana/hash.hpp>
  21
  22
  23 BOOST_HANA_NAMESPACE_BEGIN
  24     template <typename T>
  25     struct Hashable
  26         : hana::integral_constant<bool,
  27             !is_default<hash_impl<typename tag_of<T>::type>>::value
  28         >
  29     { };
  30 BOOST_HANA_NAMESPACE_END
  31
  32 #endif // !BOOST_HANA_CONCEPT_HASHABLE_HPP