xref: /llvm-project/libcxx/test/std/strings/basic.string/string.ops/string_compare/pointer.pass.cpp (revision 6e1dcc9335116f650d68cdbed12bbb34a99b2d9b)
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 // int compare(const charT *s) const; // constexpr since C++20
12 
13 #include <string>
14 #include <cassert>
15 
16 #include "test_macros.h"
17 #include "min_allocator.h"
18 
sign(int x)19 TEST_CONSTEXPR_CXX20 int sign(int x) {
20   if (x == 0)
21     return 0;
22   if (x < 0)
23     return -1;
24   return 1;
25 }
26 
27 template <class S>
test(const S & s,const typename S::value_type * str,int x)28 TEST_CONSTEXPR_CXX20 void test(const S& s, const typename S::value_type* str, int x) {
29   LIBCPP_ASSERT_NOEXCEPT(s.compare(str));
30   assert(sign(s.compare(str)) == sign(x));
31 }
32 
33 template <class S>
test_string()34 TEST_CONSTEXPR_CXX20 void test_string() {
35   test(S(""), "", 0);
36   test(S(""), "abcde", -5);
37   test(S(""), "abcdefghij", -10);
38   test(S(""), "abcdefghijklmnopqrst", -20);
39   test(S("abcde"), "", 5);
40   test(S("abcde"), "abcde", 0);
41   test(S("abcde"), "abcdefghij", -5);
42   test(S("abcde"), "abcdefghijklmnopqrst", -15);
43   test(S("abcdefghij"), "", 10);
44   test(S("abcdefghij"), "abcde", 5);
45   test(S("abcdefghij"), "abcdefghij", 0);
46   test(S("abcdefghij"), "abcdefghijklmnopqrst", -10);
47   test(S("abcdefghijklmnopqrst"), "", 20);
48   test(S("abcdefghijklmnopqrst"), "abcde", 15);
49   test(S("abcdefghijklmnopqrst"), "abcdefghij", 10);
50   test(S("abcdefghijklmnopqrst"), "abcdefghijklmnopqrst", 0);
51 }
52 
test()53 TEST_CONSTEXPR_CXX20 bool test() {
54   test_string<std::string>();
55 #if TEST_STD_VER >= 11
56   test_string<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
57 #endif
58 
59   return true;
60 }
61 
main(int,char **)62 int main(int, char**) {
63   test();
64 #if TEST_STD_VER > 17
65   static_assert(test());
66 #endif
67 
68   return 0;
69 }
70