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 int compare(const char_type* s1, const char_type* s2, size_t n);
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>::compare(L"123", L"223", 3) < 0 &&
26          std::char_traits<wchar_t>::compare(L"223", L"123", 3) > 0 &&
27          std::char_traits<wchar_t>::compare(L"123", L"123", 3) == 0;
28 }
29 #endif
30 
main(int,char **)31 int main(int, char**) {
32   assert(std::char_traits<wchar_t>::compare(L"", L"", 0) == 0);
33   assert(std::char_traits<wchar_t>::compare(NULL, NULL, 0) == 0);
34 
35   assert(std::char_traits<wchar_t>::compare(L"1", L"1", 1) == 0);
36   assert(std::char_traits<wchar_t>::compare(L"1", L"2", 1) < 0);
37   assert(std::char_traits<wchar_t>::compare(L"2", L"1", 1) > 0);
38 
39   assert(std::char_traits<wchar_t>::compare(L"12", L"12", 2) == 0);
40   assert(std::char_traits<wchar_t>::compare(L"12", L"13", 2) < 0);
41   assert(std::char_traits<wchar_t>::compare(L"12", L"22", 2) < 0);
42   assert(std::char_traits<wchar_t>::compare(L"13", L"12", 2) > 0);
43   assert(std::char_traits<wchar_t>::compare(L"22", L"12", 2) > 0);
44 
45   assert(std::char_traits<wchar_t>::compare(L"123", L"123", 3) == 0);
46   assert(std::char_traits<wchar_t>::compare(L"123", L"223", 3) < 0);
47   assert(std::char_traits<wchar_t>::compare(L"123", L"133", 3) < 0);
48   assert(std::char_traits<wchar_t>::compare(L"123", L"124", 3) < 0);
49   assert(std::char_traits<wchar_t>::compare(L"223", L"123", 3) > 0);
50   assert(std::char_traits<wchar_t>::compare(L"133", L"123", 3) > 0);
51   assert(std::char_traits<wchar_t>::compare(L"124", L"123", 3) > 0);
52 
53 #if TEST_STD_VER > 14
54   static_assert(test_constexpr(), "");
55 #endif
56 
57   return 0;
58 }
59