v1/__algorithm/ranges_generate.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___ALGORITHM_RANGES_GENERATE_H
0010 #define _LIBCPP___ALGORITHM_RANGES_GENERATE_H
0011
0012 #include <__concepts/constructible.h>
0013 #include <__concepts/invocable.h>
0014 #include <__config>
0015 #include <__iterator/concepts.h>
0016 #include <__iterator/iterator_traits.h>
0017 #include <__ranges/access.h>
0018 #include <__ranges/concepts.h>
0019 #include <__ranges/dangling.h>
0020 #include <__type_traits/invoke.h>
0021 #include <__utility/move.h>
0022
0023 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0024 #  pragma GCC system_header
0025 #endif
0026
0027 _LIBCPP_PUSH_MACROS
0028 #include <__undef_macros>
0029
0030 #if _LIBCPP_STD_VER >= 20
0031
0032 _LIBCPP_BEGIN_NAMESPACE_STD
0033
0034 namespace ranges {
0035 struct __generate {
0036   template <class _OutIter, class _Sent, class _Func>
0037   _LIBCPP_HIDE_FROM_ABI constexpr static _OutIter __generate_fn_impl(_OutIter __first, _Sent __last, _Func& __gen) {
0038     for (; __first != __last; ++__first) {
0039       *__first = __gen();
0040     }
0041
0042     return __first;
0043   }
0044
0045   template <input_or_output_iterator _OutIter, sentinel_for<_OutIter> _Sent, copy_constructible _Func>
0046     requires invocable<_Func&> && indirectly_writable<_OutIter, invoke_result_t<_Func&>>
0047   _LIBCPP_HIDE_FROM_ABI constexpr _OutIter operator()(_OutIter __first, _Sent __last, _Func __gen) const {
0048     return __generate_fn_impl(std::move(__first), std::move(__last), __gen);
0049   }
0050
0051   template <class _Range, copy_constructible _Func>
0052     requires invocable<_Func&> && output_range<_Range, invoke_result_t<_Func&>>
0053   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range> operator()(_Range&& __range, _Func __gen) const {
0054     return __generate_fn_impl(ranges::begin(__range), ranges::end(__range), __gen);
0055   }
0056 };
0057
0058 inline namespace __cpo {
0059 inline constexpr auto generate = __generate{};
0060 } // namespace __cpo
0061 } // namespace ranges
0062
0063 _LIBCPP_END_NAMESPACE_STD
0064
0065 #endif // _LIBCPP_STD_VER >= 20
0066
0067 _LIBCPP_POP_MACROS
0068
0069 #endif // _LIBCPP___ALGORITHM_RANGES_GENERATE_H