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 // void push_back(charT c) // constexpr since C++20
12 
13 #include <string>
14 #include <cassert>
15 
16 #include "test_macros.h"
17 #include "min_allocator.h"
18 
19 struct veryLarge
20 {
21   long long a;
22   char b;
23 };
24 
25 template <class S>
26 TEST_CONSTEXPR_CXX20 void
27 test(S s, typename S::value_type c, S expected)
28 {
29     s.push_back(c);
30     LIBCPP_ASSERT(s.__invariants());
31     assert(s == expected);
32 }
33 
34 TEST_CONSTEXPR_CXX20 bool test() {
35   {
36     typedef std::string S;
37     test(S(), 'a', S(1, 'a'));
38     test(S("12345"), 'a', S("12345a"));
39     test(S("12345678901234567890"), 'a', S("12345678901234567890a"));
40   }
41 #if TEST_STD_VER >= 11
42   {
43     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
44     test(S(), 'a', S(1, 'a'));
45     test(S("12345"), 'a', S("12345a"));
46     test(S("12345678901234567890"), 'a', S("12345678901234567890a"));
47   }
48 #endif
49 
50   {
51 // https://llvm.org/PR31454
52     std::basic_string<veryLarge> s;
53     veryLarge vl = {};
54     s.push_back(vl);
55     s.push_back(vl);
56     s.push_back(vl);
57   }
58 
59   return true;
60 }
61 
62 int main(int, char**)
63 {
64   test();
65 #if TEST_STD_VER > 17
66   static_assert(test());
67 #endif
68 
69   return 0;
70 }
71