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.at(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.at(0);
41         assert(r1 == 1);
42         r1 = 5.5;
43         assert(c.front() == 5.5);
44 
45         C::reference r2 = c.at(2);
46         assert(r2 == 3.5);
47         r2 = 7.5;
48         assert(c.back() == 7.5);
49 
50 #ifndef TEST_HAS_NO_EXCEPTIONS
51         try
52         {
53             (void) c.at(3);
54             assert(false);
55         }
56         catch (const std::out_of_range &) {}
57 #endif
58     }
59     {
60         typedef double T;
61         typedef std::array<T, 3> C;
62         const C c = {1, 2, 3.5};
63         C::const_reference r1 = c.at(0);
64         assert(r1 == 1);
65 
66         C::const_reference r2 = c.at(2);
67         assert(r2 == 3.5);
68 
69 #ifndef TEST_HAS_NO_EXCEPTIONS
70         try
71         {
72             (void) c.at(3);
73             assert(false);
74         }
75         catch (const std::out_of_range &) {}
76 #endif
77     }
78 
79 #if TEST_STD_VER > 11
80     {
81         typedef double T;
82         typedef std::array<T, 3> C;
83         constexpr C c = {1, 2, 3.5};
84 
85         constexpr T t1 = c.at(0);
86         static_assert (t1 == 1, "");
87 
88         constexpr T t2 = c.at(2);
89         static_assert (t2 == 3.5, "");
90     }
91 #endif
92 
93 #if TEST_STD_VER > 14
94     {
95         static_assert (check_idx(0, 1), "");
96         static_assert (check_idx(1, 2), "");
97         static_assert (check_idx(2, 3.5), "");
98     }
99 #endif
100 }
101