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<wchar_t>
12 
13 // static size_t length(const char_type* s);
14 // constexpr in C++17
15 
16 // UNSUPPORTED: no-wide-characters
17 
18 #include <string>
19 #include <cassert>
20 
21 #include "test_macros.h"
22 
23 #if TEST_STD_VER > 14
test_constexpr()24 constexpr bool test_constexpr() {
25   return std::char_traits<wchar_t>::length(L"") == 0 && std::char_traits<wchar_t>::length(L"abcd") == 4;
26 }
27 #endif
28 
main(int,char **)29 int 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 > 14
37   static_assert(test_constexpr(), "");
38 #endif
39 
40   return 0;
41 }
42