xref: /llvm-project/libcxx/test/std/strings/basic.string/string.capacity/reserve_size.pass.cpp (revision 3497500946c9b6a1b2e1452312a24c41ee412b34)
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 reserve(size_type res_arg); // constexpr since C++20
12 
13 // This test relies on https://llvm.org/PR45368 (841132e) being fixed, which isn't in
14 // older Apple dylibs.
15 // XFAIL: using-built-library-before-llvm-12
16 
17 #include <string>
18 #include <stdexcept>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 #include "min_allocator.h"
23 #include "asan_testing.h"
24 
25 template <class S>
26 TEST_CONSTEXPR_CXX20 void
test(typename S::size_type min_cap,typename S::size_type erased_index,typename S::size_type res_arg)27 test(typename S::size_type min_cap, typename S::size_type erased_index, typename S::size_type res_arg) {
28   S s(min_cap, 'a');
29   s.erase(erased_index);
30   assert(s.size() == erased_index);
31   assert(s.capacity() >= min_cap); // Check that we really have at least this capacity.
32   LIBCPP_ASSERT(is_string_asan_correct(s));
33 
34 #if TEST_STD_VER > 17
35   typename S::size_type old_cap = s.capacity();
36 #endif
37   S s0 = s;
38   if (res_arg <= s.max_size()) {
39     s.reserve(res_arg);
40     LIBCPP_ASSERT(s.__invariants());
41     assert(s == s0);
42     assert(s.capacity() >= res_arg);
43     assert(s.capacity() >= s.size());
44     LIBCPP_ASSERT(is_string_asan_correct(s));
45 #if TEST_STD_VER > 17
46     assert(s.capacity() >= old_cap); // reserve never shrinks as of P0966 (C++20)
47 #endif
48   }
49 #ifndef TEST_HAS_NO_EXCEPTIONS
50   else if (!TEST_IS_CONSTANT_EVALUATED) {
51     try {
52       s.reserve(res_arg);
53       LIBCPP_ASSERT(s.__invariants());
54       assert(false);
55     } catch (std::length_error&) {
56       assert(res_arg > s.max_size());
57     }
58   }
59 #endif
60 }
61 
62 template <class S>
test_string()63 TEST_CONSTEXPR_CXX20 void test_string() {
64   {
65     test<S>(0, 0, 5);
66     test<S>(0, 0, 10);
67     test<S>(0, 0, 50);
68   }
69   {
70     test<S>(100, 1, 5);
71     test<S>(100, 50, 5);
72     test<S>(100, 50, 10);
73     test<S>(100, 50, 50);
74     test<S>(100, 50, 100);
75     test<S>(100, 50, 1000);
76     test<S>(100, 50, S::npos);
77   }
78 }
79 
test()80 TEST_CONSTEXPR_CXX20 bool test() {
81   test_string<std::string>();
82 #if TEST_STD_VER >= 11
83   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
84 #endif
85 
86   return true;
87 }
88 
main(int,char **)89 int main(int, char**) {
90   test();
91 #if TEST_STD_VER > 17
92   static_assert(test());
93 #endif
94 
95   return 0;
96 }
97