xref: /llvm-project/libcxx/test/std/strings/basic.string/string.capacity/capacity.pass.cpp (revision 9ed20568e7de53dce85f1631d7d8c1415e7930ae)
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 // size_type capacity() const; // constexpr since C++20
12 
13 #include <string>
14 #include <cassert>
15 
16 #include "test_allocator.h"
17 #include "min_allocator.h"
18 #include "asan_testing.h"
19 
20 #include "test_macros.h"
21 
22 template <class S>
test_invariant(S s,test_allocator_statistics & alloc_stats)23 TEST_CONSTEXPR_CXX20 void test_invariant(S s, test_allocator_statistics& alloc_stats) {
24   alloc_stats.throw_after = 0;
25 #ifndef TEST_HAS_NO_EXCEPTIONS
26   try
27 #endif
28   {
29     while (s.size() < s.capacity())
30       s.push_back(typename S::value_type());
31     assert(s.size() == s.capacity());
32     LIBCPP_ASSERT(is_string_asan_correct(s));
33   }
34 #ifndef TEST_HAS_NO_EXCEPTIONS
35   catch (...) {
36     assert(false);
37   }
38 #endif
39   alloc_stats.throw_after = INT_MAX;
40 }
41 
42 template <class Alloc>
test_string(const Alloc & a)43 TEST_CONSTEXPR_CXX20 void test_string(const Alloc& a) {
44   using S = std::basic_string<char, std::char_traits<char>, Alloc>;
45   {
46     S const s((Alloc(a)));
47     assert(s.capacity() >= 0);
48     LIBCPP_ASSERT(is_string_asan_correct(s));
49   }
50   {
51     S const s(3, 'x', Alloc(a));
52     assert(s.capacity() >= 3);
53     LIBCPP_ASSERT(is_string_asan_correct(s));
54   }
55 #if TEST_STD_VER >= 11
56   // Check that we perform SSO
57   {
58     S const s;
59     assert(s.capacity() > 0);
60     ASSERT_NOEXCEPT(s.capacity());
61     LIBCPP_ASSERT(is_string_asan_correct(s));
62   }
63 #endif
64 }
65 
test()66 TEST_CONSTEXPR_CXX20 bool test() {
67   test_string(std::allocator<char>());
68   test_string(test_allocator<char>());
69   test_string(test_allocator<char>(3));
70   test_string(min_allocator<char>());
71   test_string(safe_allocator<char>());
72 
73   {
74     test_allocator_statistics alloc_stats;
75     typedef std::basic_string<char, std::char_traits<char>, test_allocator<char> > S;
76     S s((test_allocator<char>(&alloc_stats)));
77     test_invariant(s, alloc_stats);
78     LIBCPP_ASSERT(is_string_asan_correct(s));
79     s.assign(10, 'a');
80     s.erase(5);
81     test_invariant(s, alloc_stats);
82     LIBCPP_ASSERT(is_string_asan_correct(s));
83     s.assign(100, 'a');
84     s.erase(50);
85     test_invariant(s, alloc_stats);
86     LIBCPP_ASSERT(is_string_asan_correct(s));
87   }
88 
89   return true;
90 }
91 
main(int,char **)92 int main(int, char**) {
93   test();
94 #if TEST_STD_VER >= 20
95   static_assert(test());
96 #endif
97 
98   return 0;
99 }
100