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 #include <cstdint>
17 
18 #include "test_macros.h"
19 
20 struct NoDefault {
21     TEST_CONSTEXPR NoDefault(int) { }
22 };
23 
24 #if TEST_STD_VER < 11
25 struct natural_alignment {
26     long t1;
27     long long t2;
28     double t3;
29     long double t4;
30 };
31 #endif
32 
33 TEST_CONSTEXPR_CXX17 bool tests()
34 {
35     {
36         typedef double T;
37         typedef std::array<T, 3> C;
38         C c = {1, 2, 3.5};
39         ASSERT_NOEXCEPT(c.data());
40         T* p = c.data();
41         assert(p[0] == 1);
42         assert(p[1] == 2);
43         assert(p[2] == 3.5);
44     }
45     {
46         typedef double T;
47         typedef std::array<T, 0> C;
48         C c = {};
49         ASSERT_NOEXCEPT(c.data());
50         T* p = c.data();
51         (void)p;
52     }
53     {
54         typedef double T;
55         typedef std::array<const T, 0> C;
56         C c = {{}};
57         ASSERT_NOEXCEPT(c.data());
58         const T* p = c.data();
59         (void)p;
60         static_assert((std::is_same<decltype(c.data()), const T*>::value), "");
61     }
62     {
63         typedef NoDefault T;
64         typedef std::array<T, 0> C;
65         C c = {};
66         ASSERT_NOEXCEPT(c.data());
67         T* p = c.data();
68         (void)p;
69     }
70     {
71         std::array<int, 5> c = {0, 1, 2, 3, 4};
72         assert(c.data() == &c[0]);
73         assert(*c.data() == c[0]);
74     }
75 
76     return true;
77 }
78 
79 int main(int, char**)
80 {
81     tests();
82 #if TEST_STD_VER >= 17
83     static_assert(tests(), "");
84 #endif
85 
86     // Test the alignment of data()
87     {
88 #if TEST_STD_VER < 11
89         typedef natural_alignment T;
90 #else
91         typedef std::max_align_t T;
92 #endif
93         typedef std::array<T, 0> C;
94         const C c = {};
95         const T* p = c.data();
96         std::uintptr_t pint = reinterpret_cast<std::uintptr_t>(p);
97         assert(pint % TEST_ALIGNOF(T) == 0);
98     }
99     return 0;
100 }
101