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: libcpp-has-no-incomplete-ranges
12 
13 // constexpr auto begin();
14 // constexpr auto begin() const;
15 
16 #include <cassert>
17 #include <ranges>
18 
19 #include "test_macros.h"
20 #include "types.h"
21 
22 constexpr bool test() {
23   int buffer[4][4] = {{1111, 2222, 3333, 4444}, {555, 666, 777, 888}, {99, 1010, 1111, 1212}, {13, 14, 15, 16}};
24 
25   {
26     ChildView children[4] = {ChildView(buffer[0]), ChildView(buffer[1]), ChildView(buffer[2]), ChildView(buffer[3])};
27     auto jv = std::ranges::join_view(ParentView{children});
28     assert(*jv.begin() == 1111);
29   }
30 
31   {
32     CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 1), CopyableChild(buffer[3], 0)};
33     auto jv = std::ranges::join_view(ParentView{children});
34     assert(*jv.begin() == 1111);
35   }
36   // Parent is empty.
37   {
38     CopyableChild children[4] = {CopyableChild(buffer[0]), CopyableChild(buffer[1]), CopyableChild(buffer[2]), CopyableChild(buffer[3])};
39     std::ranges::join_view jv(ParentView(children, 0));
40     assert(jv.begin() == jv.end());
41   }
42   // Parent size is one.
43   {
44     CopyableChild children[1] = {CopyableChild(buffer[0])};
45     std::ranges::join_view jv(ParentView(children, 1));
46     assert(*jv.begin() == 1111);
47   }
48   // Parent and child size is one.
49   {
50     CopyableChild children[1] = {CopyableChild(buffer[0], 1)};
51     std::ranges::join_view jv(ParentView(children, 1));
52     assert(*jv.begin() == 1111);
53   }
54   // Parent size is one child is empty
55   {
56     CopyableChild children[1] = {CopyableChild(buffer[0], 0)};
57     std::ranges::join_view jv(ParentView(children, 1));
58     assert(jv.begin() == jv.end());
59   }
60   // Has all empty children.
61   {
62     CopyableChild children[4] = {CopyableChild(buffer[0], 0), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), CopyableChild(buffer[3], 0)};
63     auto jv = std::ranges::join_view(ParentView{children});
64     assert(jv.begin() == jv.end());
65   }
66   // First child is empty, others are not.
67   {
68     CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 0), CopyableChild(buffer[2], 0), CopyableChild(buffer[3], 0)};
69     auto jv = std::ranges::join_view(ParentView{children});
70     assert(*jv.begin() == 1111);
71   }
72   // Last child is empty, others are not.
73   {
74     CopyableChild children[4] = {CopyableChild(buffer[0], 4), CopyableChild(buffer[1], 4), CopyableChild(buffer[2], 4), CopyableChild(buffer[3], 0)};
75     auto jv = std::ranges::join_view(ParentView{children});
76     assert(*jv.begin() == 1111);
77   }
78 
79   {
80     std::ranges::join_view jv(buffer);
81     assert(*jv.begin() == 1111);
82   }
83 
84   {
85     const std::ranges::join_view jv(buffer);
86     assert(*jv.begin() == 1111);
87   }
88 
89   return true;
90 }
91 
92 int main(int, char**) {
93   test();
94   static_assert(test());
95 
96   return 0;
97 }
98