/usr/include/boost/hana/ext/std
Edit: /usr/include/boost/hana/ext/std/pair.hpp (2687B)
/*!
@file
Adapts `std::pair` for use with Hana.
@copyright Louis Dionne 2013-2017
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_HANA_EXT_STD_PAIR_HPP
#define BOOST_HANA_EXT_STD_PAIR_HPP
#include
#include
#include
#include
#include
#include
#ifdef BOOST_HANA_DOXYGEN_INVOKED
namespace std {
//! @ingroup group-ext-std
//! Adaptation of `std::pair` for Hana.
//!
//!
//! Modeled concepts
//! ----------------
//! A `std::pair` models exactly the same concepts as a `hana::pair`.
//! Please refer to the documentation of `hana::pair` for details.
//!
//! @include example/ext/std/pair.cpp
template
struct pair { };
}
#endif
BOOST_HANA_NAMESPACE_BEGIN
namespace ext { namespace std { struct pair_tag; }}
template
struct tag_of> {
using type = ext::std::pair_tag;
};
//////////////////////////////////////////////////////////////////////////
// Product
//////////////////////////////////////////////////////////////////////////
template <>
struct make_impl {
template
static constexpr decltype(auto) apply(X&& x, Y&& y) {
return std::make_pair(static_cast(x),
static_cast(y));
}
};
template <>
struct first_impl {
template
static constexpr T const& apply(std::pair const& p)
{ return p.first; }
template
static constexpr T& apply(std::pair& p)
{ return p.first; }
template
static constexpr T&& apply(std::pair&& p)
{ return static_cast(p.first); }
};
template <>
struct second_impl {
template
static constexpr U const& apply(std::pair const& p)
{ return p.second; }
template
static constexpr U& apply(std::pair& p)
{ return p.second; }
template
static constexpr U&& apply(std::pair&& p)
{ return static_cast(p.second); }
};
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_EXT_STD_PAIR_HPP