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// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_CONTAINERS_ADAPTERS_H_
#define BASE_CONTAINERS_ADAPTERS_H_
#include <ranges>
#include <type_traits>
#include <utility>
#include "base/compiler_specific.h"
#include "base/containers/adapters_internal.h"
namespace base {
// Returns a range adapter that exposes its elements as rvalues. When used as an
// input range, this means the values in `range` will be moved from (and
// the values potentially in an unspecified but valid state).
template <typename Range>
requires(std::ranges::input_range<Range> &&
// The elements in the input range will be consumed, so restrict this
// to non-borrowed ranges, as the elements from a borrowed range can
// outlive this call.
!std::ranges::borrowed_range<Range> &&
// Disallow input ranges if the elements cannot be moved from (e.g.
// if they are const-qualified).
std::movable<
std::remove_reference_t<std::ranges::range_reference_t<Range>>>)
auto RangeAsRvalues(Range&& range LIFETIME_BOUND) {
return internal::RangeOfRvaluesAdapter<Range>(std::forward<Range>(range));
}
// Reversed returns a container adapter usable in a range-based "for" statement
// for iterating a reversible container in reverse order.
//
// Example:
//
// std::vector<int> v = ...;
// for (int i : base::Reversed(v)) {
// // iterates through v from back to front
// }
template <typename Range>
auto Reversed(Range&& range LIFETIME_BOUND) {
return internal::ReversedAdapter<Range>(std::forward<Range>(range));
}
} // namespace base
#endif // BASE_CONTAINERS_ADAPTERS_H_
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