mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-23 21:35:04 +03:00
81 lines
2.7 KiB
C++
81 lines
2.7 KiB
C++
/*!
|
|
@file
|
|
Defines `boost::hana::concat`.
|
|
|
|
@copyright Louis Dionne 2013-2016
|
|
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_CONCAT_HPP
|
|
#define BOOST_HANA_CONCAT_HPP
|
|
|
|
#include <boost/hana/fwd/concat.hpp>
|
|
|
|
#include <boost/hana/at.hpp>
|
|
#include <boost/hana/concept/monad_plus.hpp>
|
|
#include <boost/hana/concept/sequence.hpp>
|
|
#include <boost/hana/config.hpp>
|
|
#include <boost/hana/core/dispatch.hpp>
|
|
#include <boost/hana/core/make.hpp>
|
|
#include <boost/hana/length.hpp>
|
|
|
|
#include <cstddef>
|
|
#include <type_traits>
|
|
#include <utility>
|
|
|
|
|
|
BOOST_HANA_NAMESPACE_BEGIN
|
|
//! @cond
|
|
template <typename Xs, typename Ys>
|
|
constexpr auto concat_t::operator()(Xs&& xs, Ys&& ys) const {
|
|
using M = typename hana::tag_of<Xs>::type;
|
|
using Concat = BOOST_HANA_DISPATCH_IF(concat_impl<M>,
|
|
hana::MonadPlus<M>::value &&
|
|
std::is_same<typename hana::tag_of<Ys>::type, M>::value
|
|
);
|
|
|
|
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
|
|
static_assert(std::is_same<typename hana::tag_of<Ys>::type, M>::value,
|
|
"hana::concat(xs, ys) requires 'xs' and 'ys' to have the same tag");
|
|
|
|
static_assert(hana::MonadPlus<M>::value,
|
|
"hana::concat(xs, ys) requires 'xs' and 'ys' to be MonadPlus");
|
|
#endif
|
|
|
|
return Concat::apply(static_cast<Xs&&>(xs), static_cast<Ys&&>(ys));
|
|
}
|
|
//! @endcond
|
|
|
|
template <typename M, bool condition>
|
|
struct concat_impl<M, when<condition>> : default_ {
|
|
template <typename ...Args>
|
|
static constexpr auto apply(Args&& ...) = delete;
|
|
};
|
|
|
|
template <typename S>
|
|
struct concat_impl<S, when<Sequence<S>::value>> {
|
|
template <typename Xs, typename Ys, std::size_t ...xi, std::size_t ...yi>
|
|
static constexpr auto
|
|
concat_helper(Xs&& xs, Ys&& ys, std::index_sequence<xi...>,
|
|
std::index_sequence<yi...>)
|
|
{
|
|
return hana::make<S>(
|
|
hana::at_c<xi>(static_cast<Xs&&>(xs))...,
|
|
hana::at_c<yi>(static_cast<Ys&&>(ys))...
|
|
);
|
|
}
|
|
|
|
template <typename Xs, typename Ys>
|
|
static constexpr auto apply(Xs&& xs, Ys&& ys) {
|
|
constexpr std::size_t xi = decltype(hana::length(xs))::value;
|
|
constexpr std::size_t yi = decltype(hana::length(ys))::value;
|
|
return concat_helper(static_cast<Xs&&>(xs), static_cast<Ys&&>(ys),
|
|
std::make_index_sequence<xi>{},
|
|
std::make_index_sequence<yi>{});
|
|
}
|
|
};
|
|
BOOST_HANA_NAMESPACE_END
|
|
|
|
#endif // !BOOST_HANA_CONCAT_HPP
|