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 // <string>
10
11 // const_reference operator[](size_type pos) const; // constexpr since C++20
12 // reference operator[](size_type pos); // constexpr since C++20
13
14 #include <string>
15 #include <cassert>
16
17 #include "test_macros.h"
18 #include "min_allocator.h"
19
20 template <class S>
test_string()21 TEST_CONSTEXPR_CXX20 void test_string() {
22 S s("0123456789");
23 const S& cs = s;
24 ASSERT_SAME_TYPE(decltype(s[0]), typename S::reference);
25 ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
26 LIBCPP_ASSERT_NOEXCEPT(s[0]);
27 LIBCPP_ASSERT_NOEXCEPT(cs[0]);
28 for (typename S::size_type i = 0; i < cs.size(); ++i) {
29 assert(s[i] == static_cast<char>('0' + i));
30 assert(cs[i] == s[i]);
31 }
32 assert(cs[cs.size()] == '\0');
33 const S s2 = S();
34 assert(s2[0] == '\0');
35 }
36
37 // Same, but for the string that doesn't fit into SSO.
38 template <class S>
test_string_long()39 TEST_CONSTEXPR_CXX20 void test_string_long() {
40 S s("0123456789012345678901234567890123456789");
41 const S& cs = s;
42 ASSERT_SAME_TYPE(decltype(s[0]), typename S::reference);
43 ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
44 LIBCPP_ASSERT_NOEXCEPT(s[0]);
45 LIBCPP_ASSERT_NOEXCEPT(cs[0]);
46 for (typename S::size_type i = 0; i < cs.size(); ++i) {
47 assert(s[i] == static_cast<char>('0' + (i % 10)));
48 assert(cs[i] == s[i]);
49 }
50 assert(s[33] == static_cast<char>('0' + (33 % 10)));
51 assert(cs[34] == s[34]);
52 assert(cs[cs.size()] == '\0');
53 const S s2 = S();
54 assert(s2[0] == '\0');
55 }
56
test()57 TEST_CONSTEXPR_CXX20 bool test() {
58 test_string<std::string>();
59 #if TEST_STD_VER >= 11
60 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
61 test_string_long<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
62 #endif
63
64 return true;
65 }
66
main(int,char **)67 int main(int, char**) {
68 test();
69 #if TEST_STD_VER > 17
70 static_assert(test());
71 #endif
72
73 return 0;
74 }
75