1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___ALGORITHM_UNWRAP_RANGE_H 10 #define _LIBCPP___ALGORITHM_UNWRAP_RANGE_H 11 12 #include <__algorithm/unwrap_iter.h> 13 #include <__concepts/constructible.h> 14 #include <__config> 15 #include <__iterator/concepts.h> 16 #include <__iterator/next.h> 17 #include <__utility/declval.h> 18 #include <__utility/move.h> 19 #include <__utility/pair.h> 20 21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22 # pragma GCC system_header 23 #endif 24 25 _LIBCPP_PUSH_MACROS 26 #include <__undef_macros> 27 28 _LIBCPP_BEGIN_NAMESPACE_STD 29 30 // __unwrap_range and __rewrap_range are used to unwrap ranges which may have different iterator and sentinel types. 31 // __unwrap_iter and __rewrap_iter don't work for this, because they assume that the iterator and sentinel have 32 // the same type. __unwrap_range tries to get two iterators and then forward to __unwrap_iter. 33 34 #if _LIBCPP_STD_VER >= 20 35 template <class _Iter, class _Sent> 36 struct __unwrap_range_impl { 37 _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Sent __sent) 38 requires random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter> 39 { 40 auto __last = ranges::next(__first, __sent); 41 return pair{std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))}; 42 } 43 44 _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Sent __last) { 45 return pair{std::move(__first), std::move(__last)}; 46 } 47 48 _LIBCPP_HIDE_FROM_ABI static constexpr auto 49 __rewrap(_Iter __orig_iter, decltype(std::__unwrap_iter(std::move(__orig_iter))) __iter) 50 requires random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter> 51 { 52 return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); 53 } 54 55 _LIBCPP_HIDE_FROM_ABI static constexpr auto __rewrap(const _Iter&, _Iter __iter) 56 requires(!(random_access_iterator<_Iter> && sized_sentinel_for<_Sent, _Iter>)) 57 { 58 return __iter; 59 } 60 }; 61 62 template <class _Iter> 63 struct __unwrap_range_impl<_Iter, _Iter> { 64 _LIBCPP_HIDE_FROM_ABI static constexpr auto __unwrap(_Iter __first, _Iter __last) { 65 return pair{std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))}; 66 } 67 68 _LIBCPP_HIDE_FROM_ABI static constexpr auto 69 __rewrap(_Iter __orig_iter, decltype(std::__unwrap_iter(__orig_iter)) __iter) { 70 return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); 71 } 72 }; 73 74 template <class _Iter, class _Sent> 75 _LIBCPP_HIDE_FROM_ABI constexpr auto __unwrap_range(_Iter __first, _Sent __last) { 76 return __unwrap_range_impl<_Iter, _Sent>::__unwrap(std::move(__first), std::move(__last)); 77 } 78 79 template < class _Sent, class _Iter, class _Unwrapped> 80 _LIBCPP_HIDE_FROM_ABI constexpr _Iter __rewrap_range(_Iter __orig_iter, _Unwrapped __iter) { 81 return __unwrap_range_impl<_Iter, _Sent>::__rewrap(std::move(__orig_iter), std::move(__iter)); 82 } 83 #else // _LIBCPP_STD_VER >= 20 84 template <class _Iter, class _Unwrapped = decltype(std::__unwrap_iter(std::declval<_Iter>()))> 85 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR pair<_Unwrapped, _Unwrapped> __unwrap_range(_Iter __first, _Iter __last) { 86 return std::make_pair(std::__unwrap_iter(std::move(__first)), std::__unwrap_iter(std::move(__last))); 87 } 88 89 template <class _Iter, class _Unwrapped> 90 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR _Iter __rewrap_range(_Iter __orig_iter, _Unwrapped __iter) { 91 return std::__rewrap_iter(std::move(__orig_iter), std::move(__iter)); 92 } 93 #endif // _LIBCPP_STD_VER >= 20 94 95 _LIBCPP_END_NAMESPACE_STD 96 97 _LIBCPP_POP_MACROS 98 99 #endif // _LIBCPP___ALGORITHM_UNWRAP_RANGE_H 100