axmol/thirdparty/range-v3/include/range/v3/action/stride.hpp

80 lines
2.4 KiB
C++

/// \file
// Range v3 library
//
// Copyright Eric Niebler 2013-present
//
// Use, modification and distribution is subject to 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)
//
// Project home: https://github.com/ericniebler/range-v3
//
#ifndef RANGES_V3_ACTION_STRIDE_HPP
#define RANGES_V3_ACTION_STRIDE_HPP
#include <range/v3/range_fwd.hpp>
#include <range/v3/action/action.hpp>
#include <range/v3/action/erase.hpp>
#include <range/v3/functional/bind_back.hpp>
#include <range/v3/iterator/concepts.hpp>
#include <range/v3/iterator/operations.hpp>
#include <range/v3/iterator/traits.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
/// \addtogroup group-actions
/// @{
namespace actions
{
struct stride_fn
{
template(typename D)(
requires detail::integer_like_<D>)
constexpr auto operator()(D step) const
{
return make_action_closure(bind_back(stride_fn{}, step));
}
template(typename Rng, typename D = range_difference_t<Rng>)(
requires forward_range<Rng> AND
erasable_range<Rng &, iterator_t<Rng>, sentinel_t<Rng>> AND
permutable<iterator_t<Rng>>)
Rng operator()(Rng && rng, range_difference_t<Rng> const step) const
{
using I = iterator_t<Rng>;
using S = sentinel_t<Rng>;
RANGES_EXPECT(0 < step);
if(1 < step)
{
I first = ranges::begin(rng);
S const last = ranges::end(rng);
if(first != last)
{
for(I i = ranges::next(++first, step - 1, last); i != last;
advance(i, step, last), ++first)
{
*first = iter_move(i);
}
}
ranges::actions::erase(rng, first, last);
}
return static_cast<Rng &&>(rng);
}
};
/// \relates actions::stride_fn
RANGES_INLINE_VARIABLE(stride_fn, stride)
} // namespace actions
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#endif