1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // <array>
11
12 // reference operator[] (size_type)
13 // const_reference operator[] (size_type); // constexpr in C++14
14 // reference at (size_type)
15 // const_reference at (size_type); // constexpr in C++14
16
17 #include <array>
18 #include <cassert>
19
20 #include "test_macros.h"
21
22 // std::array is explicitly allowed to be initialized with A a = { init-list };.
23 // Disable the missing braces warning for this reason.
24 #include "disable_missing_braces_warning.h"
25
26 #if TEST_STD_VER > 14
check_idx(size_t idx,double val)27 constexpr bool check_idx( size_t idx, double val )
28 {
29 std::array<double, 3> arr = {1, 2, 3.5};
30 return arr[idx] == val;
31 }
32 #endif
33
main()34 int main()
35 {
36 {
37 typedef double T;
38 typedef std::array<T, 3> C;
39 C c = {1, 2, 3.5};
40 C::reference r1 = c[0];
41 assert(r1 == 1);
42 r1 = 5.5;
43 assert(c.front() == 5.5);
44
45 C::reference r2 = c[2];
46 assert(r2 == 3.5);
47 r2 = 7.5;
48 assert(c.back() == 7.5);
49 }
50 {
51 typedef double T;
52 typedef std::array<T, 3> C;
53 const C c = {1, 2, 3.5};
54 C::const_reference r1 = c[0];
55 assert(r1 == 1);
56 C::const_reference r2 = c[2];
57 assert(r2 == 3.5);
58 }
59 { // Test operator[] "works" on zero sized arrays
60 typedef double T;
61 typedef std::array<T, 0> C;
62 C c = {};
63 C const& cc = c;
64 static_assert((std::is_same<decltype(c[0]), T &>::value), "");
65 static_assert((std::is_same<decltype(cc[0]), const T &>::value), "");
66 if (c.size() > (0)) { // always false
67 C::reference r1 = c[0];
68 C::const_reference r2 = cc[0];
69 ((void)r1);
70 ((void)r2);
71 }
72 }
73 { // Test operator[] "works" on zero sized arrays
74 typedef double T;
75 typedef std::array<const T, 0> C;
76 C c = {{}};
77 C const& cc = c;
78 static_assert((std::is_same<decltype(c[0]), const T &>::value), "");
79 static_assert((std::is_same<decltype(cc[0]), const T &>::value), "");
80 if (c.size() > (0)) { // always false
81 C::reference r1 = c[0];
82 C::const_reference r2 = cc[0];
83 ((void)r1);
84 ((void)r2);
85 }
86 }
87 #if TEST_STD_VER > 11
88 {
89 typedef double T;
90 typedef std::array<T, 3> C;
91 constexpr C c = {1, 2, 3.5};
92
93 constexpr T t1 = c[0];
94 static_assert (t1 == 1, "");
95
96 constexpr T t2 = c[2];
97 static_assert (t2 == 3.5, "");
98 }
99 #endif
100
101 #if TEST_STD_VER > 14
102 {
103 static_assert (check_idx(0, 1), "");
104 static_assert (check_idx(1, 2), "");
105 static_assert (check_idx(2, 3.5), "");
106 }
107 #endif
108 }
109