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 // reference at (size_type); // constexpr in C++17
12 
13 // GCC 5 doesn't implement the required constexpr support
14 // UNSUPPORTED: gcc-5
15 
16 #include <array>
17 #include <cassert>
18 
19 #ifndef TEST_HAS_NO_EXCEPTIONS
20 #include <stdexcept>
21 #endif
22 
23 #include "test_macros.h"
24 
25 // std::array is explicitly allowed to be initialized with A a = { init-list };.
26 // Disable the missing braces warning for this reason.
27 #include "disable_missing_braces_warning.h"
28 
29 
30 TEST_CONSTEXPR_CXX17 bool tests()
31 {
32     {
33         typedef double T;
34         typedef std::array<T, 3> C;
35         C c = {1, 2, 3.5};
36         typename C::reference r1 = c.at(0);
37         assert(r1 == 1);
38         r1 = 5.5;
39         assert(c[0] == 5.5);
40 
41         typename C::reference r2 = c.at(2);
42         assert(r2 == 3.5);
43         r2 = 7.5;
44         assert(c[2] == 7.5);
45     }
46     return true;
47 }
48 
49 void test_exceptions()
50 {
51 #ifndef TEST_HAS_NO_EXCEPTIONS
52     {
53         std::array<int, 4> array = {1, 2, 3, 4};
54 
55         try {
56             TEST_IGNORE_NODISCARD array.at(4);
57             assert(false);
58         } catch (std::out_of_range const&) {
59             // pass
60         } catch (...) {
61             assert(false);
62         }
63 
64         try {
65             TEST_IGNORE_NODISCARD array.at(5);
66             assert(false);
67         } catch (std::out_of_range const&) {
68             // pass
69         } catch (...) {
70             assert(false);
71         }
72 
73         try {
74             TEST_IGNORE_NODISCARD array.at(6);
75             assert(false);
76         } catch (std::out_of_range const&) {
77             // pass
78         } catch (...) {
79             assert(false);
80         }
81 
82         try {
83             using size_type = decltype(array)::size_type;
84             TEST_IGNORE_NODISCARD array.at(static_cast<size_type>(-1));
85             assert(false);
86         } catch (std::out_of_range const&) {
87             // pass
88         } catch (...) {
89             assert(false);
90         }
91     }
92 
93     {
94         std::array<int, 0> array = {};
95 
96         try {
97             TEST_IGNORE_NODISCARD array.at(0);
98             assert(false);
99         } catch (std::out_of_range const&) {
100             // pass
101         } catch (...) {
102             assert(false);
103         }
104     }
105 #endif
106 }
107 
108 int main(int, char**)
109 {
110     tests();
111     test_exceptions();
112 
113 #if TEST_STD_VER >= 17
114     static_assert(tests(), "");
115 #endif
116     return 0;
117 }
118