60 lines · cpp
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-exception6//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++1715 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 >= 1755 static_assert(test());56#endif57 58 return 0;59}60