42 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<wchar_t>12 13// static size_t length(const char_type* s);14// constexpr in C++1715 16// UNSUPPORTED: no-wide-characters17 18#include <string>19#include <cassert>20 21#include "test_macros.h"22 23#if TEST_STD_VER > 1424constexpr bool test_constexpr() {25 return std::char_traits<wchar_t>::length(L"") == 0 && std::char_traits<wchar_t>::length(L"abcd") == 4;26}27#endif28 29int main(int, char**) {30 assert(std::char_traits<wchar_t>::length(L"") == 0);31 assert(std::char_traits<wchar_t>::length(L"a") == 1);32 assert(std::char_traits<wchar_t>::length(L"aa") == 2);33 assert(std::char_traits<wchar_t>::length(L"aaa") == 3);34 assert(std::char_traits<wchar_t>::length(L"aaaa") == 4);35 36#if TEST_STD_VER > 1437 static_assert(test_constexpr(), "");38#endif39 40 return 0;41}42