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 // XFAIL: libcpp-no-exceptions
11 // <array>
12 
13 // reference operator[] (size_type)
14 // const_reference operator[] (size_type); // constexpr in C++14
15 // reference at (size_type)
16 // const_reference at (size_type); // constexpr in C++14
17 
18 #include <array>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
23 // std::array is explicitly allowed to be initialized with A a = { init-list };.
24 // Disable the missing braces warning for this reason.
25 #include "disable_missing_braces_warning.h"
26 
27 int main()
28 {
29     {
30         typedef double T;
31         typedef std::array<T, 3> C;
32         C c = {1, 2, 3.5};
33         C::reference r1 = c.at(0);
34         assert(r1 == 1);
35         r1 = 5.5;
36         assert(c.front() == 5.5);
37 
38         C::reference r2 = c.at(2);
39         assert(r2 == 3.5);
40         r2 = 7.5;
41         assert(c.back() == 7.5);
42 
43         try { (void) c.at(3); }
44         catch (const std::out_of_range &) {}
45     }
46     {
47         typedef double T;
48         typedef std::array<T, 3> C;
49         const C c = {1, 2, 3.5};
50         C::const_reference r1 = c.at(0);
51         assert(r1 == 1);
52 
53         C::const_reference r2 = c.at(2);
54         assert(r2 == 3.5);
55 
56         try { (void) c.at(3); }
57         catch (const std::out_of_range &) {}
58     }
59 
60 #if TEST_STD_VER > 11
61     {
62         typedef double T;
63         typedef std::array<T, 3> C;
64         constexpr C c = {1, 2, 3.5};
65 
66         constexpr T t1 = c.at(0);
67         static_assert (t1 == 1, "");
68 
69         constexpr T t2 = c.at(2);
70         static_assert (t2 == 3.5, "");
71     }
72 #endif
73 
74 }
75