| //===----------------------------------------------------------------------===// |
| // |
| // 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_RANGES_FOR_EACH_N_H |
| #define _LIBCPP___ALGORITHM_RANGES_FOR_EACH_N_H |
| |
| #include <__algorithm/in_fun_result.h> |
| #include <__config> |
| #include <__functional/identity.h> |
| #include <__functional/invoke.h> |
| #include <__iterator/concepts.h> |
| #include <__iterator/incrementable_traits.h> |
| #include <__iterator/iterator_traits.h> |
| #include <__iterator/projected.h> |
| #include <__ranges/concepts.h> |
| #include <__utility/move.h> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| #if _LIBCPP_STD_VER >= 20 |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| namespace ranges { |
| |
| template <class _Iter, class _Func> |
| using for_each_n_result = in_fun_result<_Iter, _Func>; |
| |
| namespace __for_each_n { |
| struct __fn { |
| template <input_iterator _Iter, class _Proj = identity, indirectly_unary_invocable<projected<_Iter, _Proj>> _Func> |
| _LIBCPP_HIDE_FROM_ABI constexpr for_each_n_result<_Iter, _Func> |
| operator()(_Iter __first, iter_difference_t<_Iter> __count, _Func __func, _Proj __proj = {}) const { |
| while (__count-- > 0) { |
| std::invoke(__func, std::invoke(__proj, *__first)); |
| ++__first; |
| } |
| return {std::move(__first), std::move(__func)}; |
| } |
| }; |
| } // namespace __for_each_n |
| |
| inline namespace __cpo { |
| inline constexpr auto for_each_n = __for_each_n::__fn{}; |
| } // namespace __cpo |
| } // namespace ranges |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP_STD_VER >= 20 |
| |
| #endif // _LIBCPP___ALGORITHM_RANGES_FOR_EACH_N_H |