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 // const_reference front() const; // constexpr in C++14
12 // const_reference back() const; // constexpr in C++14
13
14 #include <array>
15 #include <cassert>
16
17 #include "test_macros.h"
18
19 // std::array is explicitly allowed to be initialized with A a = { init-list };.
20 // Disable the missing braces warning for this reason.
21 #include "disable_missing_braces_warning.h"
22
23
tests()24 TEST_CONSTEXPR_CXX14 bool tests()
25 {
26 {
27 typedef double T;
28 typedef std::array<T, 3> C;
29 C const c = {1, 2, 3.5};
30 C::const_reference r1 = c.front();
31 assert(r1 == 1);
32
33 C::const_reference r2 = c.back();
34 assert(r2 == 3.5);
35 }
36 {
37 typedef double T;
38 typedef std::array<T, 0> C;
39 C const c = {};
40 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference);
41 LIBCPP_ASSERT_NOEXCEPT(c.back());
42 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference);
43 LIBCPP_ASSERT_NOEXCEPT(c.front());
44 if (c.size() > (0)) { // always false
45 TEST_IGNORE_NODISCARD c.front();
46 TEST_IGNORE_NODISCARD c.back();
47 }
48 }
49 {
50 typedef double T;
51 typedef std::array<const T, 0> C;
52 C const c = {};
53 ASSERT_SAME_TYPE(decltype(c.back()), C::const_reference);
54 LIBCPP_ASSERT_NOEXCEPT(c.back());
55 ASSERT_SAME_TYPE(decltype(c.front()), C::const_reference);
56 LIBCPP_ASSERT_NOEXCEPT(c.front());
57 if (c.size() > (0)) {
58 TEST_IGNORE_NODISCARD c.front();
59 TEST_IGNORE_NODISCARD c.back();
60 }
61 }
62
63 return true;
64 }
65
main(int,char **)66 int main(int, char**)
67 {
68 tests();
69 #if TEST_STD_VER >= 14
70 static_assert(tests(), "");
71 #endif
72 return 0;
73 }
74