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
23constexpr bool tests() {
24 // Test the explicit deduction guides
25 {
26 std::array arr{1, 2, 3}; // array(T, U...)
27 static_assert(std::is_same_v<decltype(arr), std::array<int, 3>>, "");
28 assert(arr[0] == 1);
29 assert(arr[1] == 2);
30 assert(arr[2] == 3);
31 }
32
33 {
34 const long l1 = 42;
35 std::array arr{1L, 4L, 9L, l1}; // array(T, U...)
36 static_assert(std::is_same_v<decltype(arr)::value_type, long>, "");
37 static_assert(arr.size() == 4, "");
38 assert(arr[0] == 1);
39 assert(arr[1] == 4);
40 assert(arr[2] == 9);
41 assert(arr[3] == l1);
42 }
43
44 // Test the implicit deduction guides
45 {
46 std::array<double, 2> source = {4.0, 5.0};
47 std::array arr(source); // array(array)
48 static_assert(std::is_same_v<decltype(arr), decltype(source)>, "");
49 static_assert(std::is_same_v<decltype(arr), std::array<double, 2>>, "");
50 assert(arr[0] == 4.0);
51 assert(arr[1] == 5.0);
52 }
53
54 return true;
55}
56
57int main(int, char**) {
58 tests();
59 static_assert(tests(), "");
60 return 0;
61}
62

source code of libcxx/test/std/containers/sequences/array/array.cons/deduct.pass.cpp