Sprout/sprout/tuple/tuple/tuple_size.hpp
2017-07-29 14:20:01 +09:00

69 lines
2.1 KiB
C++

/*=============================================================================
Copyright (c) 2011-2017 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_TUPLE_TUPLE_TUPLE_SIZE_HPP
#define SPROUT_TUPLE_TUPLE_TUPLE_SIZE_HPP
#include <tuple>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/type_traits/detail/type_traits_wrapper.hpp>
#include <sprout/type_traits/has_value.hpp>
#include <sprout/detail/nil_base.hpp>
namespace sprout {
namespace tuples {
//
// tuple_size
//
namespace detail {
#if defined(_MSC_VER)
template<typename T, bool = true>
#else
template<typename T, bool = sprout::has_value<std::tuple_size<T> >::value>
#endif
struct tuple_size_default;
template<typename T>
struct tuple_size_default<T, false>
: public sprout::detail::nil_base
{};
template<typename T>
struct tuple_size_default<T, true>
: public sprout::detail::type_traits_wrapper<std::tuple_size<T> >
{};
} // namespace detail
template<typename T>
struct tuple_size
: public sprout::tuples::detail::tuple_size_default<T>
{};
template<typename T>
struct tuple_size<T const>
: public sprout::tuples::tuple_size<T>
{};
template<typename T>
struct tuple_size<T volatile>
: public sprout::tuples::tuple_size<T>
{};
template<typename T>
struct tuple_size<T const volatile>
: public sprout::tuples::tuple_size<T>
{};
} // namespace tuples
using sprout::tuples::tuple_size;
#if SPROUT_USE_VARIABLE_TEMPLATES
namespace tuples {
template<typename T>
SPROUT_STATIC_CONSTEXPR std::size_t tuple_size_v = sprout::tuples::tuple_size<T>::value;
} // namespace tuples
using sprout::tuples::tuple_size_v;
#endif // #if SPROUT_USE_VARIABLE_TEMPLATES
} // namespace sprout
#endif // #ifndef SPROUT_TUPLE_TUPLE_TUPLE_SIZE_HPP