mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-23 13:22:02 +03:00
62 lines
1.8 KiB
C++
62 lines
1.8 KiB
C++
|
/*!
|
||
|
@file
|
||
|
Defines `boost::hana::find`.
|
||
|
|
||
|
@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_FIND_HPP
|
||
|
#define BOOST_HANA_FIND_HPP
|
||
|
|
||
|
#include <boost/hana/fwd/find.hpp>
|
||
|
|
||
|
#include <boost/hana/concept/searchable.hpp>
|
||
|
#include <boost/hana/config.hpp>
|
||
|
#include <boost/hana/core/dispatch.hpp>
|
||
|
#include <boost/hana/equal.hpp>
|
||
|
#include <boost/hana/find_if.hpp>
|
||
|
|
||
|
|
||
|
BOOST_HANA_NAMESPACE_BEGIN
|
||
|
//! @cond
|
||
|
template <typename Xs, typename Key>
|
||
|
constexpr auto find_t::operator()(Xs&& xs, Key const& key) const {
|
||
|
using S = typename hana::tag_of<Xs>::type;
|
||
|
using Find = BOOST_HANA_DISPATCH_IF(find_impl<S>,
|
||
|
hana::Searchable<S>::value
|
||
|
);
|
||
|
|
||
|
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
|
||
|
static_assert(hana::Searchable<S>::value,
|
||
|
"hana::find(xs, key) requires 'xs' to be Searchable");
|
||
|
#endif
|
||
|
|
||
|
return Find::apply(static_cast<Xs&&>(xs), key);
|
||
|
}
|
||
|
//! @endcond
|
||
|
|
||
|
namespace detail {
|
||
|
template <typename T>
|
||
|
struct equal_to {
|
||
|
T const& t;
|
||
|
template <typename U>
|
||
|
constexpr auto operator()(U const& u) const {
|
||
|
return hana::equal(t, u);
|
||
|
}
|
||
|
};
|
||
|
}
|
||
|
|
||
|
template <typename S, bool condition>
|
||
|
struct find_impl<S, when<condition>> : default_ {
|
||
|
template <typename Xs, typename Key>
|
||
|
static constexpr auto apply(Xs&& xs, Key const& key) {
|
||
|
return hana::find_if(static_cast<Xs&&>(xs),
|
||
|
detail::equal_to<Key>{key});
|
||
|
}
|
||
|
};
|
||
|
BOOST_HANA_NAMESPACE_END
|
||
|
|
||
|
#endif // !BOOST_HANA_FIND_HPP
|