1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___NUMERIC_RANGES_IOTA_H 11 #define _LIBCPP___NUMERIC_RANGES_IOTA_H 12 13 #include <__algorithm/out_value_result.h> 14 #include <__config> 15 #include <__iterator/concepts.h> 16 #include <__ranges/access.h> 17 #include <__ranges/concepts.h> 18 #include <__ranges/dangling.h> 19 #include <__utility/as_const.h> 20 #include <__utility/move.h> 21 22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 23 # pragma GCC system_header 24 #endif 25 26 _LIBCPP_PUSH_MACROS 27 #include <__undef_macros> 28 29 _LIBCPP_BEGIN_NAMESPACE_STD 30 31 #if _LIBCPP_STD_VER >= 23 32 namespace ranges { 33 template <typename _Out, typename _Tp> 34 using iota_result = ranges::out_value_result<_Out, _Tp>; 35 36 struct __iota_fn { 37 public: 38 template <input_or_output_iterator _Out, sentinel_for<_Out> _Sent, weakly_incrementable _Tp> 39 requires indirectly_writable<_Out, const _Tp&> operator__iota_fn40 _LIBCPP_HIDE_FROM_ABI static constexpr iota_result<_Out, _Tp> operator()(_Out __first, _Sent __last, _Tp __value) { 41 while (__first != __last) { 42 *__first = std::as_const(__value); 43 ++__first; 44 ++__value; 45 } 46 return {std::move(__first), std::move(__value)}; 47 } 48 49 template <weakly_incrementable _Tp, ranges::output_range<const _Tp&> _Range> 50 _LIBCPP_HIDE_FROM_ABI static constexpr iota_result<ranges::borrowed_iterator_t<_Range>, _Tp> operator__iota_fn51 operator()(_Range&& __r, _Tp __value) { 52 return operator()(ranges::begin(__r), ranges::end(__r), std::move(__value)); 53 } 54 }; 55 56 inline constexpr auto iota = __iota_fn{}; 57 } // namespace ranges 58 59 #endif // _LIBCPP_STD_VER >= 23 60 61 _LIBCPP_END_NAMESPACE_STD 62 63 _LIBCPP_POP_MACROS 64 65 #endif // _LIBCPP___NUMERIC_RANGES_IOTA_H 66