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 // <array>
10 // UNSUPPORTED: c++03, c++11, c++14
11 
12 // template <class T, class... U>
13 //   array(T, U...) -> array<T, 1 + sizeof...(U)>;
14 //
15 //  Requires: (is_same_v<T, U> && ...) is true. Otherwise the program is ill-formed.
16 
17 #include <array>
18 #include <cassert>
19 #include <cstddef>
20 
21 #include "test_macros.h"
22 
23 constexpr bool tests()
24 {
25     //  Test the explicit deduction guides
26     {
27         std::array arr{1,2,3};  // array(T, U...)
28         static_assert(std::is_same_v<decltype(arr), std::array<int, 3>>, "");
29         assert(arr[0] == 1);
30         assert(arr[1] == 2);
31         assert(arr[2] == 3);
32     }
33 
34     {
35         const long l1 = 42;
36         std::array arr{1L, 4L, 9L, l1}; // array(T, U...)
37         static_assert(std::is_same_v<decltype(arr)::value_type, long>, "");
38         static_assert(arr.size() == 4, "");
39         assert(arr[0] == 1);
40         assert(arr[1] == 4);
41         assert(arr[2] == 9);
42         assert(arr[3] == l1);
43     }
44 
45     //  Test the implicit deduction guides
46     {
47         std::array<double, 2> source = {4.0, 5.0};
48         std::array arr(source);   // array(array)
49         static_assert(std::is_same_v<decltype(arr), decltype(source)>, "");
50         static_assert(std::is_same_v<decltype(arr), std::array<double, 2>>, "");
51         assert(arr[0] == 4.0);
52         assert(arr[1] == 5.0);
53     }
54 
55     return true;
56 }
57 
58 int main(int, char**)
59 {
60     tests();
61     static_assert(tests(), "");
62     return 0;
63 }
64