mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-23 05:13:04 +03:00
111 lines
4.3 KiB
C++
111 lines
4.3 KiB
C++
/*!
|
|
@file
|
|
Defines `boost::hana::lexicographical_compare`.
|
|
|
|
@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_LEXICOGRAPHICAL_COMPARE_HPP
|
|
#define BOOST_HANA_LEXICOGRAPHICAL_COMPARE_HPP
|
|
|
|
#include <boost/hana/fwd/lexicographical_compare.hpp>
|
|
|
|
#include <boost/hana/bool.hpp>
|
|
#include <boost/hana/concept/iterable.hpp>
|
|
#include <boost/hana/config.hpp>
|
|
#include <boost/hana/core/dispatch.hpp>
|
|
#include <boost/hana/drop_front.hpp>
|
|
#include <boost/hana/front.hpp>
|
|
#include <boost/hana/if.hpp>
|
|
#include <boost/hana/is_empty.hpp>
|
|
#include <boost/hana/less.hpp>
|
|
|
|
|
|
BOOST_HANA_NAMESPACE_BEGIN
|
|
//! @cond
|
|
template <typename Xs, typename Ys>
|
|
constexpr auto lexicographical_compare_t::operator()(Xs const& xs, Ys const& ys) const {
|
|
return hana::lexicographical_compare(xs, ys, hana::less);
|
|
}
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
constexpr auto lexicographical_compare_t::operator()(Xs const& xs, Ys const& ys, Pred const& pred) const {
|
|
using It1 = typename hana::tag_of<Xs>::type;
|
|
using It2 = typename hana::tag_of<Ys>::type;
|
|
using LexicographicalCompare = BOOST_HANA_DISPATCH_IF(
|
|
lexicographical_compare_impl<It1>,
|
|
hana::Iterable<It1>::value &&
|
|
hana::Iterable<It2>::value
|
|
);
|
|
|
|
#ifndef BOOST_HANA_CONFIG_DISABLE_CONCEPT_CHECKS
|
|
static_assert(hana::Iterable<It1>::value,
|
|
"hana::lexicographical_compare(xs, ys, pred) requires 'xs' to be Iterable");
|
|
|
|
static_assert(hana::Iterable<It2>::value,
|
|
"hana::lexicographical_compare(xs, ys, pred) requires 'ys' to be Iterable");
|
|
#endif
|
|
|
|
return LexicographicalCompare::apply(xs, ys, pred);
|
|
}
|
|
//! @endcond
|
|
|
|
template <typename It, bool condition>
|
|
struct lexicographical_compare_impl<It, when<condition>> : default_ {
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper2(Xs const&, Ys const&, Pred const&, hana::true_)
|
|
{ return hana::false_c; }
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper2(Xs const& xs, Ys const& ys, Pred const& pred, hana::false_)
|
|
{ return apply(hana::drop_front(xs), hana::drop_front(ys), pred); }
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper2(Xs const& xs, Ys const& ys, Pred const& pred, bool is_greater)
|
|
{ return is_greater ? false : apply(hana::drop_front(xs), hana::drop_front(ys), pred); }
|
|
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper1(Xs const&, Ys const&, Pred const&, hana::true_)
|
|
{ return hana::true_c; }
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper1(Xs const& xs, Ys const& ys, Pred const& pred, hana::false_)
|
|
{ return helper2(xs, ys, pred, hana::if_(pred(hana::front(ys), hana::front(xs)), hana::true_c, hana::false_c)); }
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper1(Xs const& xs, Ys const& ys, Pred const& pred, bool is_less)
|
|
{ return is_less ? true : helper2(xs, ys, pred, hana::if_(pred(hana::front(ys), hana::front(xs)), hana::true_c, hana::false_c)); }
|
|
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper(Xs const&, Ys const& ys, Pred const&, hana::true_)
|
|
{ return hana::not_(hana::is_empty(ys)); }
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto
|
|
helper(Xs const& xs, Ys const& ys, Pred const& pred, hana::false_)
|
|
{ return helper1(xs, ys, pred, hana::if_(pred(hana::front(xs), hana::front(ys)), hana::true_c, hana::false_c)); }
|
|
|
|
|
|
template <typename Xs, typename Ys, typename Pred>
|
|
static constexpr auto apply(Xs const& xs, Ys const& ys, Pred const& pred) {
|
|
return helper(xs, ys, pred, hana::bool_c<
|
|
decltype(hana::is_empty(xs))::value ||
|
|
decltype(hana::is_empty(ys))::value
|
|
>);
|
|
}
|
|
};
|
|
BOOST_HANA_NAMESPACE_END
|
|
|
|
#endif // !BOOST_HANA_LEXICOGRAPHICAL_COMPARE_HPP
|