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_RANGES_FOR_EACH_H 10 #define _LIBCPP___ALGORITHM_RANGES_FOR_EACH_H 11 12 #include <__algorithm/for_each.h> 13 #include <__algorithm/for_each_n.h> 14 #include <__algorithm/in_fun_result.h> 15 #include <__concepts/assignable.h> 16 #include <__config> 17 #include <__functional/identity.h> 18 #include <__iterator/concepts.h> 19 #include <__iterator/projected.h> 20 #include <__ranges/access.h> 21 #include <__ranges/concepts.h> 22 #include <__ranges/dangling.h> 23 #include <__utility/move.h> 24 25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 26 # pragma GCC system_header 27 #endif 28 29 _LIBCPP_PUSH_MACROS 30 #include <__undef_macros> 31 32 #if _LIBCPP_STD_VER >= 20 33 34 _LIBCPP_BEGIN_NAMESPACE_STD 35 36 namespace ranges { 37 38 template <class _Iter, class _Func> 39 using for_each_result = in_fun_result<_Iter, _Func>; 40 41 struct __for_each { 42 private: 43 template <class _Iter, class _Sent, class _Proj, class _Func> 44 _LIBCPP_HIDE_FROM_ABI constexpr static for_each_result<_Iter, _Func> __for_each_impl__for_each45 __for_each_impl(_Iter __first, _Sent __last, _Func& __func, _Proj& __proj) { 46 // In the case where we have different iterator and sentinel types, the segmented iterator optimization 47 // in std::for_each will not kick in. Therefore, we prefer std::for_each_n in that case (whenever we can 48 // obtain the `n`). 49 if constexpr (!std::assignable_from<_Iter&, _Sent> && std::sized_sentinel_for<_Sent, _Iter>) { 50 auto __n = __last - __first; 51 auto __end = std::__for_each_n(std::move(__first), __n, __func, __proj); 52 return {std::move(__end), std::move(__func)}; 53 } else { 54 auto __end = std::__for_each(std::move(__first), std::move(__last), __func, __proj); 55 return {std::move(__end), std::move(__func)}; 56 } 57 } 58 59 public: 60 template <input_iterator _Iter, 61 sentinel_for<_Iter> _Sent, 62 class _Proj = identity, 63 indirectly_unary_invocable<projected<_Iter, _Proj>> _Func> 64 _LIBCPP_HIDE_FROM_ABI constexpr for_each_result<_Iter, _Func> operator__for_each65 operator()(_Iter __first, _Sent __last, _Func __func, _Proj __proj = {}) const { 66 return __for_each_impl(std::move(__first), std::move(__last), __func, __proj); 67 } 68 69 template <input_range _Range, 70 class _Proj = identity, 71 indirectly_unary_invocable<projected<iterator_t<_Range>, _Proj>> _Func> 72 _LIBCPP_HIDE_FROM_ABI constexpr for_each_result<borrowed_iterator_t<_Range>, _Func> operator__for_each73 operator()(_Range&& __range, _Func __func, _Proj __proj = {}) const { 74 return __for_each_impl(ranges::begin(__range), ranges::end(__range), __func, __proj); 75 } 76 }; 77 78 inline namespace __cpo { 79 inline constexpr auto for_each = __for_each{}; 80 } // namespace __cpo 81 } // namespace ranges 82 83 _LIBCPP_END_NAMESPACE_STD 84 85 #endif // _LIBCPP_STD_VER >= 20 86 87 _LIBCPP_POP_MACROS 88 89 #endif // _LIBCPP___ALGORITHM_RANGES_FOR_EACH_H 90