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 #ifndef _LIBCPP___RANGES_DATA_H
10 #define _LIBCPP___RANGES_DATA_H
11 
12 #include <__config>
13 #include <__iterator/concepts.h>
14 #include <__iterator/iterator_traits.h>
15 #include <__memory/pointer_traits.h>
16 #include <__ranges/access.h>
17 #include <__utility/forward.h>
18 #include <concepts>
19 #include <type_traits>
20 
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 #pragma GCC system_header
23 #endif
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 #if !defined(_LIBCPP_HAS_NO_RANGES)
28 
29 // [range.prim.data]
30 
31 namespace ranges {
32 namespace __data {
33   template <class _Tp>
34   concept __ptr_to_object = is_pointer_v<_Tp> && is_object_v<remove_pointer_t<_Tp>>;
35 
36   template <class _Tp>
37   concept __member_data =
38     requires(_Tp&& __t) {
39       { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
40       { __t.data() } -> __ptr_to_object;
41     };
42 
43   template <class _Tp>
44   concept __ranges_begin_invocable =
45     !__member_data<_Tp> &&
46     requires(_Tp&& __t) {
47       { _VSTD::forward<_Tp>(__t) } -> __can_borrow;
48       { ranges::begin(_VSTD::forward<_Tp>(__t)) } -> contiguous_iterator;
49     };
50 
51   struct __fn {
52     template <__member_data _Tp>
53       requires __can_borrow<_Tp>
54     _LIBCPP_HIDE_FROM_ABI
55     constexpr __ptr_to_object auto operator()(_Tp&& __t) const
56         noexcept(noexcept(__t.data())) {
57       return __t.data();
58     }
59 
60     template<__ranges_begin_invocable _Tp>
61       requires __can_borrow<_Tp>
62     _LIBCPP_HIDE_FROM_ABI
63     constexpr __ptr_to_object auto operator()(_Tp&& __t) const
64         noexcept(noexcept(_VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t))))) {
65       return _VSTD::to_address(ranges::begin(_VSTD::forward<_Tp>(__t)));
66     }
67   };
68 }
69 
70 inline namespace __cpo {
71   inline constexpr auto data = __data::__fn{};
72 } // namespace __cpo
73 } // namespace ranges
74 
75 #endif // !defined(_LIBCPP_HAS_NO_RANGES)
76 
77 _LIBCPP_END_NAMESPACE_STD
78 
79 #endif // _LIBCPP___RANGES_DATA_H
80