text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  // XFAIL: LIBCXX-AIX-FIXME
  
  // <string>
  
  // size_type rfind(charT c, size_type pos = npos) const; // constexpr since C++20
  
  #include <string>
  #include <cassert>
  
  #include "test_macros.h"
  #include "min_allocator.h"
  
  template <class S>
  TEST_CONSTEXPR_CXX20 void
  test(const S& s, typename S::value_type c, typename S::size_type pos,
       typename S::size_type x)
  {
      LIBCPP_ASSERT_NOEXCEPT(s.rfind(c, pos));
      assert(s.rfind(c, pos) == x);
      if (x != S::npos)
          assert(x <= pos && x + 1 <= s.size());
  }
  
  template <class S>
  TEST_CONSTEXPR_CXX20 void
  test(const S& s, typename S::value_type c, typename S::size_type x)
  {
      LIBCPP_ASSERT_NOEXCEPT(s.rfind(c));
      assert(s.rfind(c) == x);
      if (x != S::npos)
          assert(x + 1 <= s.size());
  }
  
  TEST_CONSTEXPR_CXX20 bool test() {
    {
      typedef std::string S;
      test(S(""), 'b', 0, S::npos);
      test(S(""), 'b', 1, S::npos);
      test(S("abcde"), 'b', 0, S::npos);
      test(S("abcde"), 'b', 1, 1);
      test(S("abcde"), 'b', 2, 1);
      test(S("abcde"), 'b', 4, 1);
      test(S("abcde"), 'b', 5, 1);
      test(S("abcde"), 'b', 6, 1);
      test(S("abcdeabcde"), 'b', 0, S::npos);
      test(S("abcdeabcde"), 'b', 1, 1);
      test(S("abcdeabcde"), 'b', 5, 1);
      test(S("abcdeabcde"), 'b', 9, 6);
      test(S("abcdeabcde"), 'b', 10, 6);
      test(S("abcdeabcde"), 'b', 11, 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 0, S::npos);
      test(S("abcdeabcdeabcdeabcde"), 'b', 1, 1);
      test(S("abcdeabcdeabcdeabcde"), 'b', 10, 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 19, 16);
      test(S("abcdeabcdeabcdeabcde"), 'b', 20, 16);
      test(S("abcdeabcdeabcdeabcde"), 'b', 21, 16);
  
      test(S(""), 'b', S::npos);
      test(S("abcde"), 'b', 1);
      test(S("abcdeabcde"), 'b', 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 16);
    }
  #if TEST_STD_VER >= 11
    {
      typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
      test(S(""), 'b', 0, S::npos);
      test(S(""), 'b', 1, S::npos);
      test(S("abcde"), 'b', 0, S::npos);
      test(S("abcde"), 'b', 1, 1);
      test(S("abcde"), 'b', 2, 1);
      test(S("abcde"), 'b', 4, 1);
      test(S("abcde"), 'b', 5, 1);
      test(S("abcde"), 'b', 6, 1);
      test(S("abcdeabcde"), 'b', 0, S::npos);
      test(S("abcdeabcde"), 'b', 1, 1);
      test(S("abcdeabcde"), 'b', 5, 1);
      test(S("abcdeabcde"), 'b', 9, 6);
      test(S("abcdeabcde"), 'b', 10, 6);
      test(S("abcdeabcde"), 'b', 11, 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 0, S::npos);
      test(S("abcdeabcdeabcdeabcde"), 'b', 1, 1);
      test(S("abcdeabcdeabcdeabcde"), 'b', 10, 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 19, 16);
      test(S("abcdeabcdeabcdeabcde"), 'b', 20, 16);
      test(S("abcdeabcdeabcdeabcde"), 'b', 21, 16);
  
      test(S(""), 'b', S::npos);
      test(S("abcde"), 'b', 1);
      test(S("abcdeabcde"), 'b', 6);
      test(S("abcdeabcdeabcdeabcde"), 'b', 16);
    }
  #endif
  
    return true;
  }
  
  int main(int, char**)
  {
    test();
  #if TEST_STD_VER > 17
    static_assert(test());
  #endif
  
    return 0;
  }
  