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 
main()20 int main()
21 {
22     {
23         typedef double T;
24         typedef std::array<T, 3> C;
25         C c = {1, 2, 3.5};
26         C::reference r1 = c[0];
27         assert(r1 == 1);
28         r1 = 5.5;
29         assert(c.front() == 5.5);
30 
31         C::reference r2 = c[2];
32         assert(r2 == 3.5);
33         r2 = 7.5;
34         assert(c.back() == 7.5);
35     }
36     {
37         typedef double T;
38         typedef std::array<T, 3> C;
39         const C c = {1, 2, 3.5};
40         C::const_reference r1 = c[0];
41         assert(r1 == 1);
42         C::const_reference r2 = c[2];
43         assert(r2 == 3.5);
44     }
45 
46 #if _LIBCPP_STD_VER > 11
47     {
48         typedef double T;
49         typedef std::array<T, 3> C;
50         constexpr C c = {1, 2, 3.5};
51 
52         constexpr T t1 = c[0];
53         static_assert (t1 == 1, "");
54 
55         constexpr T t2 = c[2];
56         static_assert (t2 == 3.5, "");
57     }
58 #endif
59 
60 }
61