1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
10 
11 // <string>
12 
13 // template<> struct char_traits<char8_t>
14 
15 // static constexpr size_t length(const char_type* s);
16 
17 #include <string>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 
22 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
test_constexpr()23 constexpr bool test_constexpr()
24 {
25     return std::char_traits<char8_t>::length(u8"") == 0
26         && std::char_traits<char8_t>::length(u8"abcd") == 4;
27 }
28 
main()29 int main()
30 {
31     assert(std::char_traits<char8_t>::length(u8"") == 0);
32     assert(std::char_traits<char8_t>::length(u8"a") == 1);
33     assert(std::char_traits<char8_t>::length(u8"aa") == 2);
34     assert(std::char_traits<char8_t>::length(u8"aaa") == 3);
35     assert(std::char_traits<char8_t>::length(u8"aaaa") == 4);
36 
37     static_assert(test_constexpr(), "");
38 }
39 #else
main()40 int main() { }
41 #endif
42