axmol/thirdparty/range-v3/include/range/v3/view/counted.hpp

128 lines
3.5 KiB
C++

/// \file
// Range v3 library
//
// Copyright Eric Niebler 2014-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_VIEW_COUNTED_HPP
#define RANGES_V3_VIEW_COUNTED_HPP
#include <utility>
#include <range/v3/range_fwd.hpp>
#include <range/v3/iterator/concepts.hpp>
#include <range/v3/iterator/counted_iterator.hpp>
#include <range/v3/iterator/default_sentinel.hpp>
#include <range/v3/iterator/traits.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/view/interface.hpp>
#include <range/v3/view/subrange.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
/// \addtogroup group-views
/// @{
template<typename I>
struct counted_view : view_interface<counted_view<I>, finite>
{
private:
friend range_access;
I it_;
iter_difference_t<I> n_;
public:
counted_view() = default;
counted_view(I it, iter_difference_t<I> n)
: it_(it)
, n_(n)
{
RANGES_EXPECT(0 <= n_);
}
counted_iterator<I> begin() const
{
return make_counted_iterator(it_, n_);
}
default_sentinel_t end() const
{
return {};
}
auto size() const
{
return static_cast<detail::iter_size_t<I>>(n_);
}
};
template<typename I>
RANGES_INLINE_VAR constexpr bool enable_borrowed_range<counted_view<I>> = true;
#if RANGES_CXX_DEDUCTION_GUIDES >= RANGES_CXX_DEDUCTION_GUIDES_17
template<typename I>
counted_view(I, iter_difference_t<I>)
-> counted_view<I>;
#endif
namespace views
{
struct cpp20_counted_fn
{
template(typename I)(
requires input_or_output_iterator<I> AND (!random_access_iterator<I>)) //
subrange<counted_iterator<I>, default_sentinel_t> //
operator()(I it, iter_difference_t<I> n) const
{
return {make_counted_iterator(std::move(it), n), default_sentinel};
}
template(typename I)(
requires random_access_iterator<I>)
subrange<I> operator()(I it, iter_difference_t<I> n) const
{
return {it, it + n};
}
};
struct counted_fn
{
template(typename I)(
requires input_or_output_iterator<I> AND (!random_access_iterator<I>)) //
counted_view<I> operator()(I it, iter_difference_t<I> n) const
{
return {std::move(it), n};
}
template(typename I)(
requires random_access_iterator<I>)
subrange<I> operator()(I it, iter_difference_t<I> n) const
{
return {it, it + n};
}
};
/// \relates counted_fn
/// \ingroup group-views
RANGES_INLINE_VARIABLE(counted_fn, counted)
} // namespace views
namespace cpp20
{
namespace views
{
RANGES_INLINE_VARIABLE(ranges::views::cpp20_counted_fn, counted)
}
} // namespace cpp20
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#include <range/v3/detail/satisfy_boost_range.hpp>
RANGES_SATISFY_BOOST_RANGE(::ranges::counted_view)
#endif