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: c++03, c++11, c++14, c++17, c++20
10
11// <string>
12
13// constexpr basic_string substr(size_type pos = 0, size_type n = npos) &&;
14
15#include <algorithm>
16#include <stdexcept>
17#include <string>
18
19#include "constexpr_char_traits.h"
20#include "make_string.h"
21#include "min_allocator.h"
22#include "test_allocator.h"
23#include "asan_testing.h"
24
25#define STR(string) MAKE_CSTRING(typename S::value_type, string)
26
27constexpr struct should_throw_exception_t {
28} should_throw_exception;
29
30template <class S>
31constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, const S expected) {
32 S str = std::move(orig).substr(pos, n);
33 LIBCPP_ASSERT(orig.__invariants());
34 LIBCPP_ASSERT(str.__invariants());
35 assert(str == expected);
36 LIBCPP_ASSERT(is_string_asan_correct(orig));
37 LIBCPP_ASSERT(is_string_asan_correct(str));
38}
39
40template <class S>
41constexpr void test(S orig, typename S::size_type pos, typename S::size_type n, should_throw_exception_t) {
42#ifndef TEST_HAS_NO_EXCEPTIONS
43 if (!std::is_constant_evaluated()) {
44 try {
45 S str = std::move(orig).substr(pos, n);
46 assert(false);
47 } catch (const std::out_of_range&) {
48 }
49 }
50#else
51 (void)orig;
52 (void)pos;
53 (void)n;
54#endif
55}
56
57template <class S>
58constexpr void test_string() {
59 test<S>(STR(""), 0, 0, STR(""));
60 test<S>(STR(""), 0, 1, STR(""));
61 test<S>(STR(""), 1, 0, should_throw_exception);
62 test<S>(STR(""), 1, 1, should_throw_exception);
63 test<S>(STR("short string"), 0, 1, STR("s"));
64 test<S>(STR("short string"), 5, 5, STR(" stri"));
65 test<S>(STR("short string"), 12, 5, STR(""));
66 test<S>(STR("short string"), 13, 5, should_throw_exception);
67 test<S>(STR("long long string so no SSO"), 0, 0, STR(""));
68 test<S>(STR("long long string so no SSO"), 0, 10, STR("long long "));
69 test<S>(STR("long long string so no SSO"), 10, 10, STR("string so "));
70 test<S>(STR("long long string so no SSO"), 20, 10, STR("no SSO"));
71 test<S>(STR("long long string so no SSO"), 26, 10, STR(""));
72 test<S>(STR("long long string so no SSO"), 27, 0, should_throw_exception);
73}
74
75template <class CharT, class CharTraits>
76constexpr void test_allocators() {
77 test_string<std::basic_string<CharT, CharTraits, std::allocator<CharT>>>();
78 test_string<std::basic_string<CharT, CharTraits, min_allocator<CharT>>>();
79 test_string<std::basic_string<CharT, CharTraits, test_allocator<CharT>>>();
80}
81
82template <class CharT>
83constexpr void test_char_traits() {
84 test_allocators<CharT, std::char_traits<CharT>>();
85 test_allocators<CharT, constexpr_char_traits<CharT>>();
86}
87
88constexpr bool test() {
89 test_char_traits<char>();
90 test_char_traits<char16_t>();
91 test_char_traits<char32_t>();
92#ifndef TEST_HAS_NO_WIDE_CHARACTERS
93 test_char_traits<wchar_t>();
94#endif
95#ifndef TEST_HAS_NO_CHAR8_T
96 test_char_traits<char8_t>();
97#endif
98
99 return true;
100}
101
102int main(int, char**) {
103 test();
104 static_assert(test());
105
106 return 0;
107}
108

source code of libcxx/test/std/strings/basic.string/string.ops/string_substr/substr_rvalue.pass.cpp