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/// \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_REVERSE_HPP
#define RANGES_V3_VIEW_REVERSE_HPP
#include <iterator>
#include <utility>
#include <meta/meta.hpp>
#include <range/v3/range_fwd.hpp>
#include <range/v3/iterator/operations.hpp>
#include <range/v3/iterator/reverse_iterator.hpp>
#include <range/v3/range/access.hpp>
#include <range/v3/range/primitives.hpp>
#include <range/v3/range/traits.hpp>
#include <range/v3/utility/box.hpp>
#include <range/v3/utility/get.hpp>
#include <range/v3/utility/optional.hpp>
#include <range/v3/utility/static_const.hpp>
#include <range/v3/view/adaptor.hpp>
#include <range/v3/view/all.hpp>
#include <range/v3/view/view.hpp>
#include <range/v3/detail/prologue.hpp>
namespace ranges
{
/// \addtogroup group-views
/// @{
template<typename Rng>
struct RANGES_EMPTY_BASES reverse_view
: view_interface<reverse_view<Rng>, range_cardinality<Rng>::value>
, private detail::non_propagating_cache<iterator_t<Rng>, reverse_view<Rng>,
!common_range<Rng>>
{
private:
CPP_assert(bidirectional_range<Rng>);
Rng rng_;
constexpr reverse_iterator<iterator_t<Rng>> begin_(std::true_type)
{
return make_reverse_iterator(ranges::end(rng_));
}
constexpr reverse_iterator<iterator_t<Rng>> begin_(std::false_type)
{
using cache_t =
detail::non_propagating_cache<iterator_t<Rng>, reverse_view<Rng>>;
auto & end_ = static_cast<cache_t &>(*this);
if(!end_)
{
#if defined(_MSC_VER)
auto tmp = ranges::begin(rng_);
auto e = ranges::end(rng_);
while(tmp != e)
++tmp;
#else
auto tmp = ranges::next(ranges::begin(rng_), ranges::end(rng_));
#endif
end_ = std::move(tmp);
}
return make_reverse_iterator(*end_);
}
public:
reverse_view() = default;
constexpr explicit reverse_view(Rng rng)
: rng_(detail::move(rng))
{}
Rng base() const
{
return rng_;
}
constexpr reverse_iterator<iterator_t<Rng>> begin()
{
return begin_(meta::bool_<(bool)common_range<Rng>>{});
}
template(bool Const = true)(
requires Const AND common_range<meta::const_if_c<Const, Rng>>)
constexpr reverse_iterator<iterator_t<meta::const_if_c<Const, Rng>>> begin() const
{
return make_reverse_iterator(ranges::end(rng_));
}
constexpr reverse_iterator<iterator_t<Rng>> end()
{
return make_reverse_iterator(ranges::begin(rng_));
}
template(bool Const = true)(
requires Const AND common_range<meta::const_if_c<Const, Rng>>)
constexpr reverse_iterator<iterator_t<meta::const_if_c<Const, Rng>>> end() const
{
return make_reverse_iterator(ranges::begin(rng_));
}
CPP_auto_member
constexpr auto CPP_fun(size)()(
requires sized_range<Rng>)
{
return ranges::size(rng_);
}
CPP_auto_member
constexpr auto CPP_fun(size)()(const //
requires sized_range<Rng const>)
{
return ranges::size(rng_);
}
};
template<typename Rng>
struct reverse_view<reverse_view<Rng>> : Rng
{
CPP_assert(bidirectional_range<Rng>);
CPP_assert(
same_as<detail::decay_t<decltype(std::declval<reverse_view<Rng>>().base())>,
Rng>);
reverse_view() = default;
constexpr explicit reverse_view(reverse_view<Rng> rng)
: Rng(rng.base())
{}
constexpr reverse_view<Rng> base() const
{
return reverse_view<Rng>{*this};
}
};
template<typename Rng>
RANGES_INLINE_VAR constexpr bool enable_borrowed_range<reverse_view<Rng>> =
enable_borrowed_range<Rng>;
#if RANGES_CXX_DEDUCTION_GUIDES >= RANGES_CXX_DEDUCTION_GUIDES_17
template<typename Rng>
reverse_view(Rng &&) //
-> reverse_view<views::all_t<Rng>>;
template<typename Rng>
reverse_view(reverse_view<Rng>)
-> reverse_view<reverse_view<Rng>>;
#endif
namespace views
{
struct reverse_fn
{
template(typename Rng)(
requires viewable_range<Rng> AND bidirectional_range<Rng>)
constexpr reverse_view<all_t<Rng>> operator()(Rng && rng) const
{
return reverse_view<all_t<Rng>>{all(static_cast<Rng &&>(rng))};
}
};
/// \relates reverse_fn
/// \ingroup group-views
RANGES_INLINE_VARIABLE(view_closure<reverse_fn>, reverse)
} // namespace views
namespace cpp20
{
namespace views
{
using ranges::views::reverse;
}
template(typename Rng)(
requires view_<Rng> AND bidirectional_range<Rng>)
using reverse_view = ranges::reverse_view<Rng>;
} // namespace cpp20
/// @}
} // namespace ranges
#include <range/v3/detail/epilogue.hpp>
#include <range/v3/detail/satisfy_boost_range.hpp>
RANGES_SATISFY_BOOST_RANGE(::ranges::reverse_view)
#endif
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