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 // T *data();
12 
13 #include <array>
14 #include <cassert>
15 #include <cstddef>       // for std::max_align_t
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 struct NoDefault {
24   NoDefault(int) {}
25 };
26 
27 
28 int main(int, char**)
29 {
30     {
31         typedef double T;
32         typedef std::array<T, 3> C;
33         C c = {1, 2, 3.5};
34         T* p = c.data();
35         assert(p[0] == 1);
36         assert(p[1] == 2);
37         assert(p[2] == 3.5);
38     }
39     {
40         typedef double T;
41         typedef std::array<T, 0> C;
42         C c = {};
43         T* p = c.data();
44         LIBCPP_ASSERT(p != nullptr);
45     }
46     {
47       typedef double T;
48       typedef std::array<const T, 0> C;
49       C c = {{}};
50       const T* p = c.data();
51       static_assert((std::is_same<decltype(c.data()), const T*>::value), "");
52       LIBCPP_ASSERT(p != nullptr);
53     }
54   {
55       typedef std::max_align_t T;
56       typedef std::array<T, 0> C;
57       const C c = {};
58       const T* p = c.data();
59       LIBCPP_ASSERT(p != nullptr);
60       std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
61       assert(pint % TEST_ALIGNOF(std::max_align_t) == 0);
62     }
63     {
64       typedef NoDefault T;
65       typedef std::array<T, 0> C;
66       C c = {};
67       T* p = c.data();
68       LIBCPP_ASSERT(p != nullptr);
69     }
70 
71   return 0;
72 }
73