xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/ranges_generate.h (revision b3edf4467982447620505a28fc82e38a414c07dc)
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_GENERATE_H
10 #define _LIBCPP___ALGORITHM_RANGES_GENERATE_H
11 
12 #include <__concepts/constructible.h>
13 #include <__concepts/invocable.h>
14 #include <__config>
15 #include <__functional/invoke.h>
16 #include <__iterator/concepts.h>
17 #include <__iterator/iterator_traits.h>
18 #include <__ranges/access.h>
19 #include <__ranges/concepts.h>
20 #include <__ranges/dangling.h>
21 #include <__utility/move.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29 
30 #if _LIBCPP_STD_VER >= 20
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 namespace __generate {
36 
37 struct __fn {
38   template <class _OutIter, class _Sent, class _Func>
39   _LIBCPP_HIDE_FROM_ABI constexpr static _OutIter __generate_fn_impl(_OutIter __first, _Sent __last, _Func& __gen) {
40     for (; __first != __last; ++__first) {
41       *__first = __gen();
42     }
43 
44     return __first;
45   }
46 
47   template <input_or_output_iterator _OutIter, sentinel_for<_OutIter> _Sent, copy_constructible _Func>
48     requires invocable<_Func&> && indirectly_writable<_OutIter, invoke_result_t<_Func&>>
49   _LIBCPP_HIDE_FROM_ABI constexpr _OutIter operator()(_OutIter __first, _Sent __last, _Func __gen) const {
50     return __generate_fn_impl(std::move(__first), std::move(__last), __gen);
51   }
52 
53   template <class _Range, copy_constructible _Func>
54     requires invocable<_Func&> && output_range<_Range, invoke_result_t<_Func&>>
55   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_iterator_t<_Range> operator()(_Range&& __range, _Func __gen) const {
56     return __generate_fn_impl(ranges::begin(__range), ranges::end(__range), __gen);
57   }
58 };
59 
60 } // namespace __generate
61 
62 inline namespace __cpo {
63 inline constexpr auto generate = __generate::__fn{};
64 } // namespace __cpo
65 } // namespace ranges
66 
67 _LIBCPP_END_NAMESPACE_STD
68 
69 #endif // _LIBCPP_STD_VER >= 20
70 
71 _LIBCPP_POP_MACROS
72 
73 #endif // _LIBCPP___ALGORITHM_RANGES_GENERATE_H
74