| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___ALGORITHM_UNWRAP_RANGE_H |
| #define _LIBCPP___ALGORITHM_UNWRAP_RANGE_H |
| |
| #include <__algorithm/unwrap_iter.h> |
| #include <__concepts/constructible.h> |
| #include <__config> |
| #include <__iterator/concepts.h> |
| #include <__iterator/next.h> |
| #include <__utility/declval.h> |
| #include <__utility/move.h> |
| #include <__utility/pair.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| // __unwrap_range and __rewrap_range are used to unwrap ranges which may have different iterator and sentinel types. |
| // __unwrap_iter and __rewrap_iter don't work for this, because they assume that the iterator and sentinel have |
| // the same type. __unwrap_range tries to get two iterators and then forward to __unwrap_iter. |
| |
| #if _LIBCPP_STD_VER >= 20 |
| template <class _Iter, class _Sent> |
| struct __unwrap_range_impl { |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Sent __sent) |
| requires random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter> |
| { |
| auto __last = ranges::next(__first, __sent); |
| return pair{std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))}; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Sent __last) { |
| return pair{std::move(__first), std::move(__last)}; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __rewrap(_Iter __orig_iter, decltype(std::__unwrap_iter(std::move(__orig_iter))) __iter) |
| requires random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter> |
| { |
| return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __rewrap(const _Iter&, _Iter __iter) |
| requires (!(random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter>)) |
| { |
| return __iter; |
| } |
| }; |
| |
| template <class _Iter> |
| struct __unwrap_range_impl<_Iter, _Iter> { |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Iter __last) { |
| return pair{std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))}; |
| } |
| |
| _LIBCPP_HIDE_FROM_ABI static constexpr auto |
| __rewrap(_Iter __orig_iter, decltype(std::__unwrap_iter(__orig_iter)) __iter) { |
| return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); |
| } |
| }; |
| |
| template <class _Iter, class _Sent> |
| _LIBCPP_HIDE_FROM_ABI constexpr auto __unwrap_range(_Iter __first, _Sent __last) { |
| return __unwrap_range_impl<_Iter, _Sent>::__unwrap(std::move(__first), std::move(__last)); |
| } |
| |
| template < |
| class _Sent, |
| class _Iter, |
| class _Unwrapped = decltype(std::__unwrap_range(std::declval<_Iter>(), std::declval<_Sent>()))> |
| _LIBCPP_HIDE_FROM_ABI constexpr _Iter __rewrap_range(_Iter __orig_iter, _Unwrapped __iter) { |
| return __unwrap_range_impl<_Iter, _Sent>::__rewrap(std::move(__orig_iter), std::move(__iter)); |
| } |
| #else // _LIBCPP_STD_VER >= 20 |
| template <class _Iter, class _Unwrapped = decltype(std::__unwrap_iter(std::declval<_Iter>()))> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR pair<_Unwrapped, _Unwrapped> __unwrap_range(_Iter __first, _Iter __last) { |
| return std::make_pair(std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))); |
| } |
| |
| template <class _Iter, class _Unwrapped = decltype(std::__unwrap_iter(std::declval<_Iter>()))> |
| _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Iter __rewrap_range(_Iter __orig_iter, _Unwrapped __iter) { |
| return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); |
| } |
| #endif // _LIBCPP_STD_VER >= 20 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ALGORITHM_UNWRAP_RANGE_H |