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// UNSUPPORTED: no-exceptions
10
11// XFAIL: FROZEN-CXX03-HEADERS-FIXME
12
13// <string>
14
15// size_type max_size() const; // constexpr since C++20
16
17// NOTE: asan and msan will fail for one of two reasons
18// 1. If allocator_may_return_null=0 then they will fail because the allocation
19// returns null.
20// 2. If allocator_may_return_null=1 then they will fail because the allocation
21// is too large to succeed.
22// UNSUPPORTED: sanitizer-new-delete
23
24#include <string>
25#include <cassert>
26#include <new>
27
28#include "test_macros.h"
29#include "min_allocator.h"
30
31template <class S>
32TEST_CONSTEXPR_CXX20 void test_resize_max_size_minus_1(const S& s) {
33 S s2(s);
34 const std::size_t sz = s2.max_size() - 1;
35 try {
36 s2.resize(sz, 'x');
37 } catch (const std::bad_alloc&) {
38 return;
39 }
40 assert(s2.size() == sz);
41}
42
43template <class S>
44TEST_CONSTEXPR_CXX20 void test_resize_max_size(const S& s) {
45 S s2(s);
46 const std::size_t sz = s2.max_size();
47 try {
48 s2.resize(sz, 'x');
49 } catch (const std::bad_alloc&) {
50 return;
51 }
52 assert(s2.size() == sz);
53}
54
55template <class S>
56TEST_CONSTEXPR_CXX20 void test_string() {
57 {
58 S s;
59 assert(s.max_size() >= s.size());
60 assert(s.max_size() > 0);
61 if (!TEST_IS_CONSTANT_EVALUATED) {
62 test_resize_max_size_minus_1(s);
63 test_resize_max_size(s);
64 }
65 }
66 {
67 S s("123");
68 assert(s.max_size() >= s.size());
69 assert(s.max_size() > 0);
70 if (!TEST_IS_CONSTANT_EVALUATED) {
71 test_resize_max_size_minus_1(s);
72 test_resize_max_size(s);
73 }
74 }
75 {
76 S s("12345678901234567890123456789012345678901234567890");
77 assert(s.max_size() >= s.size());
78 assert(s.max_size() > 0);
79 if (!TEST_IS_CONSTANT_EVALUATED) {
80 test_resize_max_size_minus_1(s);
81 test_resize_max_size(s);
82 }
83 }
84}
85
86TEST_CONSTEXPR_CXX20 bool test() {
87 test_string<std::string>();
88#if TEST_STD_VER >= 11
89 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
90 test_string<std::basic_string<char, std::char_traits<char>, tiny_size_allocator<64, char> > >();
91#endif
92
93 { // Test resizing where we can assume that the allocation succeeds
94 std::basic_string<char, std::char_traits<char>, tiny_size_allocator<32, char> > str;
95 auto max_size = str.max_size();
96 str.resize(max_size);
97 assert(str.size() == max_size);
98 }
99
100 return true;
101}
102
103int main(int, char**) {
104 test();
105#if TEST_STD_VER >= 20
106 static_assert(test());
107#endif
108
109 return 0;
110}
111

source code of libcxx/test/std/strings/basic.string/string.capacity/max_size.pass.cpp