Sprout/sprout/optional/hash.hpp
2016-02-25 18:48:28 +09:00

47 lines
1.3 KiB
C++

/*=============================================================================
Copyright (c) 2011-2016 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
=============================================================================*/
#ifndef SPROUT_OPTIONAL_HASH_HPP
#define SPROUT_OPTIONAL_HASH_HPP
#include <functional>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/optional/optional.hpp>
#include <sprout/functional/hash.hpp>
namespace sprout {
//
// hash_value
//
template<typename T>
inline SPROUT_CONSTEXPR std::size_t
hash_value(sprout::optional<T> const& v) {
return v.is_initialized() ? sprout::to_hash(*v)
: 0
;
}
} // namespace sprout
namespace std {
#if defined(__clang__)
# pragma clang diagnostic push
# pragma clang diagnostic ignored "-Wmismatched-tags"
#endif
//
// hash
//
template<typename T>
struct hash<sprout::optional<T> >
: public sprout::hash<sprout::optional<T> >
{};
#if defined(__clang__)
# pragma clang diagnostic pop
#endif
} // namespace std
#endif // #ifndef SPROUT_OPTIONAL_HASH_HPP