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 | |
11 | // reference operator[](size_type); // constexpr in C++17 |
12 | // Libc++ marks it as noexcept |
13 | |
14 | #include <array> |
15 | #include <cassert> |
16 | |
17 | #include "test_macros.h" |
18 | |
19 | TEST_CONSTEXPR_CXX17 bool tests() { |
20 | { |
21 | typedef double T; |
22 | typedef std::array<T, 3> C; |
23 | C c = {1, 2, 3.5}; |
24 | LIBCPP_ASSERT_NOEXCEPT(c[0]); |
25 | ASSERT_SAME_TYPE(C::reference, decltype(c[0])); |
26 | C::reference r1 = c[0]; |
27 | assert(r1 == 1); |
28 | r1 = 5.5; |
29 | assert(c.front() == 5.5); |
30 | |
31 | C::reference r2 = c[2]; |
32 | assert(r2 == 3.5); |
33 | r2 = 7.5; |
34 | assert(c.back() == 7.5); |
35 | } |
36 | |
37 | // Test operator[] "works" on zero sized arrays |
38 | { |
39 | { |
40 | typedef double T; |
41 | typedef std::array<T, 0> C; |
42 | C c = {}; |
43 | LIBCPP_ASSERT_NOEXCEPT(c[0]); |
44 | ASSERT_SAME_TYPE(C::reference, decltype(c[0])); |
45 | if (c.size() > (0)) { // always false |
46 | C::reference r = c[0]; |
47 | (void)r; |
48 | } |
49 | } |
50 | { |
51 | typedef double T; |
52 | typedef std::array<const T, 0> C; |
53 | C c = {}; |
54 | LIBCPP_ASSERT_NOEXCEPT(c[0]); |
55 | ASSERT_SAME_TYPE(C::reference, decltype(c[0])); |
56 | if (c.size() > (0)) { // always false |
57 | C::reference r = c[0]; |
58 | (void)r; |
59 | } |
60 | } |
61 | } |
62 | |
63 | return true; |
64 | } |
65 | |
66 | int main(int, char**) { |
67 | tests(); |
68 | #if TEST_STD_VER >= 17 |
69 | static_assert(tests(), "" ); |
70 | #endif |
71 | return 0; |
72 | } |
73 | |