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 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 // UNSUPPORTED: libcpp-no-concepts
11 // UNSUPPORTED: gcc-10
12 
13 // std::views::all;
14 
15 #include <ranges>
16 
17 #include <cassert>
18 #include "test_macros.h"
19 #include "test_iterators.h"
20 
21 int globalBuff[8];
22 
23 template<bool IsNoexcept>
24 struct View : std::ranges::view_base {
25   int start_ = 0;
26   explicit View() noexcept(IsNoexcept) = default;
27   constexpr explicit View(int start) : start_(start) {}
28   View(View&&) noexcept(IsNoexcept) = default;
29   View& operator=(View&&) noexcept(IsNoexcept) = default;
30   friend constexpr int* begin(View& view) { return globalBuff + view.start_; }
31   friend constexpr int* begin(View const& view) { return globalBuff + view.start_; }
32   friend constexpr int* end(View&) { return globalBuff + 8; }
33   friend constexpr int* end(View const&) { return globalBuff + 8; }
34 };
35 static_assert(std::ranges::view<View<true>>);
36 static_assert(std::ranges::view<View<false>>);
37 
38 template<bool IsNoexcept>
39 struct CopyableView : std::ranges::view_base {
40   int start_ = 0;
41   explicit CopyableView() noexcept(IsNoexcept) = default;
42   CopyableView(CopyableView const&) noexcept(IsNoexcept) = default;
43   CopyableView& operator=(CopyableView const&) noexcept(IsNoexcept) = default;
44   constexpr explicit CopyableView(int start) noexcept : start_(start) {}
45   friend constexpr int* begin(CopyableView& view) { return globalBuff + view.start_; }
46   friend constexpr int* begin(CopyableView const& view) { return globalBuff + view.start_; }
47   friend constexpr int* end(CopyableView&) { return globalBuff + 8; }
48   friend constexpr int* end(CopyableView const&) { return globalBuff + 8; }
49 };
50 static_assert(std::ranges::view<CopyableView<true>>);
51 static_assert(std::ranges::view<CopyableView<false>>);
52 
53 struct Range {
54   int start_;
55   constexpr explicit Range(int start) noexcept : start_(start) {}
56   friend constexpr int* begin(Range const& range) { return globalBuff + range.start_; }
57   friend constexpr int* begin(Range& range) { return globalBuff + range.start_; }
58   friend constexpr int* end(Range const&) { return globalBuff + 8; }
59   friend constexpr int* end(Range&) { return globalBuff + 8; }
60 };
61 
62 struct BorrowableRange {
63   int start_;
64   constexpr explicit BorrowableRange(int start) noexcept : start_(start) {}
65   friend constexpr int* begin(BorrowableRange const& range) { return globalBuff + range.start_; }
66   friend constexpr int* begin(BorrowableRange& range) { return globalBuff + range.start_; }
67   friend constexpr int* end(BorrowableRange const&) { return globalBuff + 8; }
68   friend constexpr int* end(BorrowableRange&) { return globalBuff + 8; }
69 };
70 template<>
71 inline constexpr bool std::ranges::enable_borrowed_range<BorrowableRange> = true;
72 
73 struct RandomAccessRange {
74   struct sentinel {
75     friend constexpr bool operator==(sentinel, const random_access_iterator<int*> rai) { return rai.base() == globalBuff + 8; }
76     friend constexpr std::ptrdiff_t operator-(sentinel, random_access_iterator<int*>) { return -8; }
77     friend constexpr std::ptrdiff_t operator-(random_access_iterator<int*>, sentinel) { return 8; }
78   };
79 
80   constexpr random_access_iterator<int*> begin() { return random_access_iterator<int*>{globalBuff}; }
81   constexpr sentinel end() { return {}; }
82 };
83 template<>
84 inline constexpr bool std::ranges::enable_borrowed_range<RandomAccessRange> = true;
85 
86 constexpr bool test() {
87   {
88     ASSERT_SAME_TYPE(decltype(std::views::all(View<true>())), View<true>);
89     static_assert(noexcept(std::views::all(View<true>())));
90     static_assert(!noexcept(std::views::all(View<false>())));
91 
92     auto viewCopy = std::views::all(View<true>(2));
93     ASSERT_SAME_TYPE(decltype(viewCopy), View<true>);
94     assert(std::ranges::begin(viewCopy) == globalBuff + 2);
95     assert(std::ranges::end(viewCopy) == globalBuff + 8);
96   }
97 
98   {
99     ASSERT_SAME_TYPE(decltype(std::views::all(std::declval<const CopyableView<true>&>())), CopyableView<true>);
100     static_assert(noexcept(std::views::all(CopyableView<true>())));
101     static_assert(!noexcept(std::views::all(CopyableView<false>())));
102 
103     CopyableView<true> view(2);
104     auto viewCopy = std::views::all(view);
105     ASSERT_SAME_TYPE(decltype(viewCopy), CopyableView<true>);
106     assert(std::ranges::begin(viewCopy) == globalBuff + 2);
107     assert(std::ranges::end(viewCopy) == globalBuff + 8);
108   }
109 
110   {
111     Range range(2);
112     auto ref = std::views::all(range);
113     ASSERT_SAME_TYPE(decltype(ref), std::ranges::ref_view<Range>);
114     assert(std::ranges::begin(ref) == globalBuff + 2);
115     assert(std::ranges::end(ref) == globalBuff + 8);
116 
117     static_assert(!std::is_invocable_v<decltype(std::views::all), Range>);
118   }
119 
120   {
121     const Range range(2);
122     auto ref = std::views::all(range);
123     static_assert(!noexcept(std::views::all(range)));
124     ASSERT_SAME_TYPE(decltype(ref), std::ranges::ref_view<const Range>);
125     assert(std::ranges::begin(ref) == globalBuff + 2);
126     assert(std::ranges::end(ref) == globalBuff + 8);
127   }
128 
129   {
130     auto subrange = std::views::all(BorrowableRange(2));
131     static_assert(!noexcept(std::views::all(BorrowableRange(2))));
132     ASSERT_SAME_TYPE(decltype(subrange), std::ranges::subrange<int*>);
133     assert(std::ranges::begin(subrange) == globalBuff + 2);
134     assert(std::ranges::end(subrange) == globalBuff + 8);
135   }
136 
137   {
138     auto subrange = std::views::all(RandomAccessRange());
139     ASSERT_SAME_TYPE(decltype(subrange),
140                      std::ranges::subrange<random_access_iterator<int*>, RandomAccessRange::sentinel>);
141     assert(std::ranges::begin(subrange).base() == globalBuff);
142     assert(std::ranges::end(subrange) == std::ranges::begin(subrange) + 8);
143   }
144 
145   return true;
146 }
147 
148 int main(int, char**) {
149   test();
150   static_assert(test());
151 
152   return 0;
153 }
154