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
25template <class S>
26TEST_CONSTEXPR_CXX20 void
27test(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
62template <class S>
63TEST_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 { // Check that growing twice works as expected
80 S str;
81 str.reserve(50);
82 assert(str.capacity() >= 50);
83 size_t old_cap = str.capacity();
84 str.reserve(str.capacity() + 1);
85 assert(str.capacity() > old_cap);
86 }
87}
88
89TEST_CONSTEXPR_CXX20 bool test() {
90 test_string<std::string>();
91#if TEST_STD_VER >= 11
92 test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char>>>();
93#endif
94
95 return true;
96}
97
98int main(int, char**) {
99 test();
100#if TEST_STD_VER > 17
101 static_assert(test());
102#endif
103
104 return 0;
105}
106

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