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 front(); // constexpr in C++17 |
12 | // reference back(); // constexpr in C++17 |
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 | |
25 | C::reference r1 = c.front(); |
26 | assert(r1 == 1); |
27 | r1 = 5.5; |
28 | assert(c[0] == 5.5); |
29 | |
30 | C::reference r2 = c.back(); |
31 | assert(r2 == 3.5); |
32 | r2 = 7.5; |
33 | assert(c[2] == 7.5); |
34 | } |
35 | { |
36 | typedef double T; |
37 | typedef std::array<T, 0> C; |
38 | C c = {}; |
39 | ASSERT_SAME_TYPE(decltype(c.back()), C::reference); |
40 | LIBCPP_ASSERT_NOEXCEPT(c.back()); |
41 | ASSERT_SAME_TYPE(decltype(c.front()), C::reference); |
42 | LIBCPP_ASSERT_NOEXCEPT(c.front()); |
43 | if (c.size() > (0)) { // always false |
44 | TEST_IGNORE_NODISCARD c.front(); |
45 | TEST_IGNORE_NODISCARD c.back(); |
46 | } |
47 | } |
48 | { |
49 | typedef double T; |
50 | typedef std::array<const T, 0> C; |
51 | C c = {}; |
52 | ASSERT_SAME_TYPE(decltype(c.back()), C::reference); |
53 | LIBCPP_ASSERT_NOEXCEPT(c.back()); |
54 | ASSERT_SAME_TYPE(decltype(c.front()), C::reference); |
55 | LIBCPP_ASSERT_NOEXCEPT(c.front()); |
56 | if (c.size() > (0)) { |
57 | TEST_IGNORE_NODISCARD c.front(); |
58 | TEST_IGNORE_NODISCARD c.back(); |
59 | } |
60 | } |
61 | |
62 | return true; |
63 | } |
64 | |
65 | int main(int, char**) { |
66 | tests(); |
67 | #if TEST_STD_VER >= 17 |
68 | static_assert(tests(), "" ); |
69 | #endif |
70 | return 0; |
71 | } |
72 | |