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// template<> struct char_traits<char>
12
13// static int compare(const char_type* s1, const char_type* s2, size_t n);
14// constexpr in C++17
15
16#include <string>
17#include <cassert>
18
19#include "test_macros.h"
20
21TEST_CONSTEXPR_CXX17 bool test() {
22 assert(std::char_traits<char>::compare("", "", 0) == 0);
23 assert(std::char_traits<char>::compare(NULL, NULL, 0) == 0);
24
25 assert(std::char_traits<char>::compare("1", "1", 1) == 0);
26 assert(std::char_traits<char>::compare("1", "2", 1) < 0);
27 assert(std::char_traits<char>::compare("2", "1", 1) > 0);
28
29 assert(std::char_traits<char>::compare("12", "12", 2) == 0);
30 assert(std::char_traits<char>::compare("12", "13", 2) < 0);
31 assert(std::char_traits<char>::compare("12", "22", 2) < 0);
32 assert(std::char_traits<char>::compare("13", "12", 2) > 0);
33 assert(std::char_traits<char>::compare("22", "12", 2) > 0);
34
35 assert(std::char_traits<char>::compare("123", "123", 3) == 0);
36 assert(std::char_traits<char>::compare("123", "223", 3) < 0);
37 assert(std::char_traits<char>::compare("123", "133", 3) < 0);
38 assert(std::char_traits<char>::compare("123", "124", 3) < 0);
39 assert(std::char_traits<char>::compare("223", "123", 3) > 0);
40 assert(std::char_traits<char>::compare("133", "123", 3) > 0);
41 assert(std::char_traits<char>::compare("124", "123", 3) > 0);
42
43 {
44 char a[] = {static_cast<char>(-1), 0};
45 char b[] = {1, 0};
46 assert(std::char_traits<char>::compare(a, b, 1) > 0);
47 }
48
49 return true;
50}
51
52int main(int, char**) {
53 test();
54#if TEST_STD_VER >= 17
55 static_assert(test());
56#endif
57
58 return 0;
59}
60

source code of libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char/compare.pass.cpp