libcxx/test/std/strings/basic.string/string.ops/string_compare/string_view.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 basic_string_view sv) 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, class SV>
  28 TEST_CONSTEXPR_CXX20 void test(const S& s, SV sv, int x) {
  29   LIBCPP_ASSERT_NOEXCEPT(s.compare(sv));
  30   assert(sign(s.compare(sv)) == sign(x));
  31 }
  32
  33 template <class CharT, template <class> class Alloc>
  34 TEST_CONSTEXPR_CXX20 void test_string() {
  35   using S  = std::basic_string<CharT, std::char_traits<CharT>, Alloc<CharT> >;
  36   using SV = std::basic_string_view<CharT, std::char_traits<CharT> >;
  37
  38   test(S(""), SV(""), 0);
  39   test(S(""), SV("abcde"), -5);
  40   test(S(""), SV("abcdefghij"), -10);
  41   test(S(""), SV("abcdefghijklmnopqrst"), -20);
  42   test(S("abcde"), SV(""), 5);
  43   test(S("abcde"), SV("abcde"), 0);
  44   test(S("abcde"), SV("abcdefghij"), -5);
  45   test(S("abcde"), SV("abcdefghijklmnopqrst"), -15);
  46   test(S("abcdefghij"), SV(""), 10);
  47   test(S("abcdefghij"), SV("abcde"), 5);
  48   test(S("abcdefghij"), SV("abcdefghij"), 0);
  49   test(S("abcdefghij"), SV("abcdefghijklmnopqrst"), -10);
  50   test(S("abcdefghijklmnopqrst"), SV(""), 20);
  51   test(S("abcdefghijklmnopqrst"), SV("abcde"), 15);
  52   test(S("abcdefghijklmnopqrst"), SV("abcdefghij"), 10);
  53   test(S("abcdefghijklmnopqrst"), SV("abcdefghijklmnopqrst"), 0);
  54 }
  55
  56 TEST_CONSTEXPR_CXX20 bool test() {
  57   test_string<char, std::allocator>();
  58 #if TEST_STD_VER >= 11
  59   test_string<char, min_allocator>();
  60 #endif
  61
  62   return true;
  63 }
  64
  65 int main(int, char**) {
  66   test();
  67 #if TEST_STD_VER > 17
  68   static_assert(test());
  69 #endif
  70
  71   return 0;
  72 }