libcxx/test/std/strings/basic.string/string.ops/string_compare/pointer.pass.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-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
  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>
  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>
  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
  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
  62 int main(int, char**) {
  63   test();
  64 #if TEST_STD_VER > 17
  65   static_assert(test());
  66 #endif
  67
  68   return 0;
  69 }