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 #if TEST_STD_VER < 11
28 struct natural_alignment {
29     long t1;
30     long long t2;
31     double t3;
32     long double t4;
33 };
34 #endif
35 
36 int main(int, char**)
37 {
38     {
39         typedef double T;
40         typedef std::array<T, 3> C;
41         C c = {1, 2, 3.5};
42         T* p = c.data();
43         assert(p[0] == 1);
44         assert(p[1] == 2);
45         assert(p[2] == 3.5);
46     }
47     {
48         typedef double T;
49         typedef std::array<T, 0> C;
50         C c = {};
51         T* p = c.data();
52         LIBCPP_ASSERT(p != nullptr);
53     }
54     {
55       typedef double T;
56       typedef std::array<const T, 0> C;
57       C c = {{}};
58       const T* p = c.data();
59       static_assert((std::is_same<decltype(c.data()), const T*>::value), "");
60       LIBCPP_ASSERT(p != nullptr);
61     }
62   {
63 #if TEST_STD_VER < 11
64       typedef natural_alignment T;
65 #else
66       typedef std::max_align_t T;
67 #endif
68       typedef std::array<T, 0> C;
69       const C c = {};
70       const T* p = c.data();
71       LIBCPP_ASSERT(p != nullptr);
72       std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
73       assert(pint % TEST_ALIGNOF(T) == 0);
74     }
75     {
76       typedef NoDefault T;
77       typedef std::array<T, 0> C;
78       C c = {};
79       T* p = c.data();
80       LIBCPP_ASSERT(p != nullptr);
81     }
82 
83   return 0;
84 }
85