//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

// <string>

// int compare(size_type pos1, size_type n1, const basic_string& str) const; // constexpr since C++20

#include <string>
#include <stdexcept>
#include <cassert>

#include "test_macros.h"
#include "min_allocator.h"

TEST_CONSTEXPR_CXX20 int sign(int x) {
  if (x == 0)
    return 0;
  if (x < 0)
    return -1;
  return 1;
}

template <class S>
TEST_CONSTEXPR_CXX20 void test(const S& s, typename S::size_type pos1, typename S::size_type n1, const S& str, int x) {
  if (pos1 <= s.size())
    assert(sign(s.compare(pos1, n1, str)) == sign(x));
#ifndef TEST_HAS_NO_EXCEPTIONS
  else if (!TEST_IS_CONSTANT_EVALUATED) {
    try {
      TEST_IGNORE_NODISCARD s.compare(pos1, n1, str);
      assert(false);
    } catch (std::out_of_range&) {
      assert(pos1 > s.size());
    }
  }
#endif
}

template <class S>
TEST_CONSTEXPR_CXX20 bool test0() {
  test(S(""), 0, 0, S(""), 0);
  test(S(""), 0, 0, S("abcde"), -5);
  test(S(""), 0, 0, S("abcdefghij"), -10);
  test(S(""), 0, 0, S("abcdefghijklmnopqrst"), -20);
  test(S(""), 0, 1, S(""), 0);
  test(S(""), 0, 1, S("abcde"), -5);
  test(S(""), 0, 1, S("abcdefghij"), -10);
  test(S(""), 0, 1, S("abcdefghijklmnopqrst"), -20);
  test(S(""), 1, 0, S(""), 0);
  test(S(""), 1, 0, S("abcde"), 0);
  test(S(""), 1, 0, S("abcdefghij"), 0);
  test(S(""), 1, 0, S("abcdefghijklmnopqrst"), 0);
  test(S("abcde"), 0, 0, S(""), 0);
  test(S("abcde"), 0, 0, S("abcde"), -5);
  test(S("abcde"), 0, 0, S("abcdefghij"), -10);
  test(S("abcde"), 0, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcde"), 0, 1, S(""), 1);
  test(S("abcde"), 0, 1, S("abcde"), -4);
  test(S("abcde"), 0, 1, S("abcdefghij"), -9);
  test(S("abcde"), 0, 1, S("abcdefghijklmnopqrst"), -19);
  test(S("abcde"), 0, 2, S(""), 2);
  test(S("abcde"), 0, 2, S("abcde"), -3);
  test(S("abcde"), 0, 2, S("abcdefghij"), -8);
  test(S("abcde"), 0, 2, S("abcdefghijklmnopqrst"), -18);
  test(S("abcde"), 0, 4, S(""), 4);
  test(S("abcde"), 0, 4, S("abcde"), -1);
  test(S("abcde"), 0, 4, S("abcdefghij"), -6);
  test(S("abcde"), 0, 4, S("abcdefghijklmnopqrst"), -16);
  test(S("abcde"), 0, 5, S(""), 5);
  test(S("abcde"), 0, 5, S("abcde"), 0);
  test(S("abcde"), 0, 5, S("abcdefghij"), -5);
  test(S("abcde"), 0, 5, S("abcdefghijklmnopqrst"), -15);
  test(S("abcde"), 0, 6, S(""), 5);
  test(S("abcde"), 0, 6, S("abcde"), 0);
  test(S("abcde"), 0, 6, S("abcdefghij"), -5);
  test(S("abcde"), 0, 6, S("abcdefghijklmnopqrst"), -15);
  test(S("abcde"), 1, 0, S(""), 0);
  test(S("abcde"), 1, 0, S("abcde"), -5);
  test(S("abcde"), 1, 0, S("abcdefghij"), -10);
  test(S("abcde"), 1, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcde"), 1, 1, S(""), 1);
  test(S("abcde"), 1, 1, S("abcde"), 1);
  test(S("abcde"), 1, 1, S("abcdefghij"), 1);
  test(S("abcde"), 1, 1, S("abcdefghijklmnopqrst"), 1);
  test(S("abcde"), 1, 2, S(""), 2);
  test(S("abcde"), 1, 2, S("abcde"), 1);
  test(S("abcde"), 1, 2, S("abcdefghij"), 1);
  test(S("abcde"), 1, 2, S("abcdefghijklmnopqrst"), 1);
  test(S("abcde"), 1, 3, S(""), 3);
  test(S("abcde"), 1, 3, S("abcde"), 1);
  test(S("abcde"), 1, 3, S("abcdefghij"), 1);
  test(S("abcde"), 1, 3, S("abcdefghijklmnopqrst"), 1);
  test(S("abcde"), 1, 4, S(""), 4);
  test(S("abcde"), 1, 4, S("abcde"), 1);
  test(S("abcde"), 1, 4, S("abcdefghij"), 1);
  test(S("abcde"), 1, 4, S("abcdefghijklmnopqrst"), 1);
  test(S("abcde"), 1, 5, S(""), 4);
  test(S("abcde"), 1, 5, S("abcde"), 1);
  test(S("abcde"), 1, 5, S("abcdefghij"), 1);
  test(S("abcde"), 1, 5, S("abcdefghijklmnopqrst"), 1);
  test(S("abcde"), 2, 0, S(""), 0);
  test(S("abcde"), 2, 0, S("abcde"), -5);
  test(S("abcde"), 2, 0, S("abcdefghij"), -10);
  test(S("abcde"), 2, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcde"), 2, 1, S(""), 1);
  test(S("abcde"), 2, 1, S("abcde"), 2);
  test(S("abcde"), 2, 1, S("abcdefghij"), 2);
  test(S("abcde"), 2, 1, S("abcdefghijklmnopqrst"), 2);
  test(S("abcde"), 2, 2, S(""), 2);
  test(S("abcde"), 2, 2, S("abcde"), 2);
  test(S("abcde"), 2, 2, S("abcdefghij"), 2);
  test(S("abcde"), 2, 2, S("abcdefghijklmnopqrst"), 2);
  test(S("abcde"), 2, 3, S(""), 3);
  test(S("abcde"), 2, 3, S("abcde"), 2);
  test(S("abcde"), 2, 3, S("abcdefghij"), 2);
  test(S("abcde"), 2, 3, S("abcdefghijklmnopqrst"), 2);
  test(S("abcde"), 2, 4, S(""), 3);
  test(S("abcde"), 2, 4, S("abcde"), 2);
  test(S("abcde"), 2, 4, S("abcdefghij"), 2);
  test(S("abcde"), 2, 4, S("abcdefghijklmnopqrst"), 2);
  test(S("abcde"), 4, 0, S(""), 0);
  test(S("abcde"), 4, 0, S("abcde"), -5);
  test(S("abcde"), 4, 0, S("abcdefghij"), -10);
  test(S("abcde"), 4, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcde"), 4, 1, S(""), 1);
  test(S("abcde"), 4, 1, S("abcde"), 4);
  test(S("abcde"), 4, 1, S("abcdefghij"), 4);
  test(S("abcde"), 4, 1, S("abcdefghijklmnopqrst"), 4);
  test(S("abcde"), 4, 2, S(""), 1);
  test(S("abcde"), 4, 2, S("abcde"), 4);
  test(S("abcde"), 4, 2, S("abcdefghij"), 4);
  test(S("abcde"), 4, 2, S("abcdefghijklmnopqrst"), 4);
  test(S("abcde"), 5, 0, S(""), 0);
  test(S("abcde"), 5, 0, S("abcde"), -5);
  test(S("abcde"), 5, 0, S("abcdefghij"), -10);
  test(S("abcde"), 5, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcde"), 5, 1, S(""), 0);
  test(S("abcde"), 5, 1, S("abcde"), -5);
  test(S("abcde"), 5, 1, S("abcdefghij"), -10);
  test(S("abcde"), 5, 1, S("abcdefghijklmnopqrst"), -20);
  return true;
}

template <class S>
TEST_CONSTEXPR_CXX20 bool test1() {
  test(S("abcde"), 6, 0, S(""), 0);
  test(S("abcde"), 6, 0, S("abcde"), 0);
  test(S("abcde"), 6, 0, S("abcdefghij"), 0);
  test(S("abcde"), 6, 0, S("abcdefghijklmnopqrst"), 0);
  test(S("abcdefghij"), 0, 0, S(""), 0);
  test(S("abcdefghij"), 0, 0, S("abcde"), -5);
  test(S("abcdefghij"), 0, 0, S("abcdefghij"), -10);
  test(S("abcdefghij"), 0, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 0, 1, S(""), 1);
  test(S("abcdefghij"), 0, 1, S("abcde"), -4);
  test(S("abcdefghij"), 0, 1, S("abcdefghij"), -9);
  test(S("abcdefghij"), 0, 1, S("abcdefghijklmnopqrst"), -19);
  test(S("abcdefghij"), 0, 5, S(""), 5);
  test(S("abcdefghij"), 0, 5, S("abcde"), 0);
  test(S("abcdefghij"), 0, 5, S("abcdefghij"), -5);
  test(S("abcdefghij"), 0, 5, S("abcdefghijklmnopqrst"), -15);
  test(S("abcdefghij"), 0, 9, S(""), 9);
  test(S("abcdefghij"), 0, 9, S("abcde"), 4);
  test(S("abcdefghij"), 0, 9, S("abcdefghij"), -1);
  test(S("abcdefghij"), 0, 9, S("abcdefghijklmnopqrst"), -11);
  test(S("abcdefghij"), 0, 10, S(""), 10);
  test(S("abcdefghij"), 0, 10, S("abcde"), 5);
  test(S("abcdefghij"), 0, 10, S("abcdefghij"), 0);
  test(S("abcdefghij"), 0, 10, S("abcdefghijklmnopqrst"), -10);
  test(S("abcdefghij"), 0, 11, S(""), 10);
  test(S("abcdefghij"), 0, 11, S("abcde"), 5);
  test(S("abcdefghij"), 0, 11, S("abcdefghij"), 0);
  test(S("abcdefghij"), 0, 11, S("abcdefghijklmnopqrst"), -10);
  test(S("abcdefghij"), 1, 0, S(""), 0);
  test(S("abcdefghij"), 1, 0, S("abcde"), -5);
  test(S("abcdefghij"), 1, 0, S("abcdefghij"), -10);
  test(S("abcdefghij"), 1, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 1, 1, S(""), 1);
  test(S("abcdefghij"), 1, 1, S("abcde"), 1);
  test(S("abcdefghij"), 1, 1, S("abcdefghij"), 1);
  test(S("abcdefghij"), 1, 1, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghij"), 1, 4, S(""), 4);
  test(S("abcdefghij"), 1, 4, S("abcde"), 1);
  test(S("abcdefghij"), 1, 4, S("abcdefghij"), 1);
  test(S("abcdefghij"), 1, 4, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghij"), 1, 8, S(""), 8);
  test(S("abcdefghij"), 1, 8, S("abcde"), 1);
  test(S("abcdefghij"), 1, 8, S("abcdefghij"), 1);
  test(S("abcdefghij"), 1, 8, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghij"), 1, 9, S(""), 9);
  test(S("abcdefghij"), 1, 9, S("abcde"), 1);
  test(S("abcdefghij"), 1, 9, S("abcdefghij"), 1);
  test(S("abcdefghij"), 1, 9, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghij"), 1, 10, S(""), 9);
  test(S("abcdefghij"), 1, 10, S("abcde"), 1);
  test(S("abcdefghij"), 1, 10, S("abcdefghij"), 1);
  test(S("abcdefghij"), 1, 10, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghij"), 5, 0, S(""), 0);
  test(S("abcdefghij"), 5, 0, S("abcde"), -5);
  test(S("abcdefghij"), 5, 0, S("abcdefghij"), -10);
  test(S("abcdefghij"), 5, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 5, 1, S(""), 1);
  test(S("abcdefghij"), 5, 1, S("abcde"), 5);
  test(S("abcdefghij"), 5, 1, S("abcdefghij"), 5);
  test(S("abcdefghij"), 5, 1, S("abcdefghijklmnopqrst"), 5);
  test(S("abcdefghij"), 5, 2, S(""), 2);
  test(S("abcdefghij"), 5, 2, S("abcde"), 5);
  test(S("abcdefghij"), 5, 2, S("abcdefghij"), 5);
  test(S("abcdefghij"), 5, 2, S("abcdefghijklmnopqrst"), 5);
  test(S("abcdefghij"), 5, 4, S(""), 4);
  test(S("abcdefghij"), 5, 4, S("abcde"), 5);
  test(S("abcdefghij"), 5, 4, S("abcdefghij"), 5);
  test(S("abcdefghij"), 5, 4, S("abcdefghijklmnopqrst"), 5);
  test(S("abcdefghij"), 5, 5, S(""), 5);
  test(S("abcdefghij"), 5, 5, S("abcde"), 5);
  test(S("abcdefghij"), 5, 5, S("abcdefghij"), 5);
  test(S("abcdefghij"), 5, 5, S("abcdefghijklmnopqrst"), 5);
  test(S("abcdefghij"), 5, 6, S(""), 5);
  test(S("abcdefghij"), 5, 6, S("abcde"), 5);
  test(S("abcdefghij"), 5, 6, S("abcdefghij"), 5);
  test(S("abcdefghij"), 5, 6, S("abcdefghijklmnopqrst"), 5);
  test(S("abcdefghij"), 9, 0, S(""), 0);
  test(S("abcdefghij"), 9, 0, S("abcde"), -5);
  test(S("abcdefghij"), 9, 0, S("abcdefghij"), -10);
  test(S("abcdefghij"), 9, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 9, 1, S(""), 1);
  test(S("abcdefghij"), 9, 1, S("abcde"), 9);
  test(S("abcdefghij"), 9, 1, S("abcdefghij"), 9);
  test(S("abcdefghij"), 9, 1, S("abcdefghijklmnopqrst"), 9);
  test(S("abcdefghij"), 9, 2, S(""), 1);
  test(S("abcdefghij"), 9, 2, S("abcde"), 9);
  test(S("abcdefghij"), 9, 2, S("abcdefghij"), 9);
  test(S("abcdefghij"), 9, 2, S("abcdefghijklmnopqrst"), 9);
  test(S("abcdefghij"), 10, 0, S(""), 0);
  test(S("abcdefghij"), 10, 0, S("abcde"), -5);
  test(S("abcdefghij"), 10, 0, S("abcdefghij"), -10);
  test(S("abcdefghij"), 10, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 10, 1, S(""), 0);
  test(S("abcdefghij"), 10, 1, S("abcde"), -5);
  test(S("abcdefghij"), 10, 1, S("abcdefghij"), -10);
  test(S("abcdefghij"), 10, 1, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghij"), 11, 0, S(""), 0);
  test(S("abcdefghij"), 11, 0, S("abcde"), 0);
  test(S("abcdefghij"), 11, 0, S("abcdefghij"), 0);
  test(S("abcdefghij"), 11, 0, S("abcdefghijklmnopqrst"), 0);
  return true;
}

template <class S>
TEST_CONSTEXPR_CXX20 bool test2() {
  test(S("abcdefghijklmnopqrst"), 0, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 0, 0, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 0, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 0, 1, S(""), 1);
  test(S("abcdefghijklmnopqrst"), 0, 1, S("abcde"), -4);
  test(S("abcdefghijklmnopqrst"), 0, 1, S("abcdefghij"), -9);
  test(S("abcdefghijklmnopqrst"), 0, 1, S("abcdefghijklmnopqrst"), -19);
  test(S("abcdefghijklmnopqrst"), 0, 10, S(""), 10);
  test(S("abcdefghijklmnopqrst"), 0, 10, S("abcde"), 5);
  test(S("abcdefghijklmnopqrst"), 0, 10, S("abcdefghij"), 0);
  test(S("abcdefghijklmnopqrst"), 0, 10, S("abcdefghijklmnopqrst"), -10);
  test(S("abcdefghijklmnopqrst"), 0, 19, S(""), 19);
  test(S("abcdefghijklmnopqrst"), 0, 19, S("abcde"), 14);
  test(S("abcdefghijklmnopqrst"), 0, 19, S("abcdefghij"), 9);
  test(S("abcdefghijklmnopqrst"), 0, 19, S("abcdefghijklmnopqrst"), -1);
  test(S("abcdefghijklmnopqrst"), 0, 20, S(""), 20);
  test(S("abcdefghijklmnopqrst"), 0, 20, S("abcde"), 15);
  test(S("abcdefghijklmnopqrst"), 0, 20, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 0, 20, S("abcdefghijklmnopqrst"), 0);
  test(S("abcdefghijklmnopqrst"), 0, 21, S(""), 20);
  test(S("abcdefghijklmnopqrst"), 0, 21, S("abcde"), 15);
  test(S("abcdefghijklmnopqrst"), 0, 21, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 0, 21, S("abcdefghijklmnopqrst"), 0);
  test(S("abcdefghijklmnopqrst"), 1, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 1, 0, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 1, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 1, 1, S(""), 1);
  test(S("abcdefghijklmnopqrst"), 1, 1, S("abcde"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 1, S("abcdefghij"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 1, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 9, S(""), 9);
  test(S("abcdefghijklmnopqrst"), 1, 9, S("abcde"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 9, S("abcdefghij"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 9, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 18, S(""), 18);
  test(S("abcdefghijklmnopqrst"), 1, 18, S("abcde"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 18, S("abcdefghij"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 18, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 19, S(""), 19);
  test(S("abcdefghijklmnopqrst"), 1, 19, S("abcde"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 19, S("abcdefghij"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 19, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 20, S(""), 19);
  test(S("abcdefghijklmnopqrst"), 1, 20, S("abcde"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 20, S("abcdefghij"), 1);
  test(S("abcdefghijklmnopqrst"), 1, 20, S("abcdefghijklmnopqrst"), 1);
  test(S("abcdefghijklmnopqrst"), 10, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 10, 0, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 10, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 10, 1, S(""), 1);
  test(S("abcdefghijklmnopqrst"), 10, 1, S("abcde"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 1, S("abcdefghijklmnopqrst"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 5, S(""), 5);
  test(S("abcdefghijklmnopqrst"), 10, 5, S("abcde"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 5, S("abcdefghijklmnopqrst"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 9, S(""), 9);
  test(S("abcdefghijklmnopqrst"), 10, 9, S("abcde"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 9, S("abcdefghijklmnopqrst"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 10, S(""), 10);
  test(S("abcdefghijklmnopqrst"), 10, 10, S("abcde"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 10, S("abcdefghijklmnopqrst"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 11, S(""), 10);
  test(S("abcdefghijklmnopqrst"), 10, 11, S("abcde"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 11, S("abcdefghij"), 10);
  test(S("abcdefghijklmnopqrst"), 10, 11, S("abcdefghijklmnopqrst"), 10);
  test(S("abcdefghijklmnopqrst"), 19, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 19, 0, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 19, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 19, 1, S(""), 1);
  test(S("abcdefghijklmnopqrst"), 19, 1, S("abcde"), 19);
  test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghij"), 19);
  test(S("abcdefghijklmnopqrst"), 19, 1, S("abcdefghijklmnopqrst"), 19);
  test(S("abcdefghijklmnopqrst"), 19, 2, S(""), 1);
  test(S("abcdefghijklmnopqrst"), 19, 2, S("abcde"), 19);
  test(S("abcdefghijklmnopqrst"), 19, 2, S("abcdefghij"), 19);
  test(S("abcdefghijklmnopqrst"), 19, 2, S("abcdefghijklmnopqrst"), 19);
  test(S("abcdefghijklmnopqrst"), 20, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 20, 0, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 20, 0, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 20, 1, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 20, 1, S("abcde"), -5);
  test(S("abcdefghijklmnopqrst"), 20, 1, S("abcdefghij"), -10);
  test(S("abcdefghijklmnopqrst"), 20, 1, S("abcdefghijklmnopqrst"), -20);
  test(S("abcdefghijklmnopqrst"), 21, 0, S(""), 0);
  test(S("abcdefghijklmnopqrst"), 21, 0, S("abcde"), 0);
  test(S("abcdefghijklmnopqrst"), 21, 0, S("abcdefghij"), 0);
  test(S("abcdefghijklmnopqrst"), 21, 0, S("abcdefghijklmnopqrst"), 0);
  return true;
}

template <class S>
void test() {
  test0<S>();
  test1<S>();
  test2<S>();

#if TEST_STD_VER > 17
  static_assert(test0<S>());
  static_assert(test1<S>());
  static_assert(test2<S>());
#endif
}

int main(int, char**) {
  test<std::string>();
#if TEST_STD_VER >= 11
  test<std::basic_string<char, std::char_traits<char>, min_allocator<char> > >();
  { // LWG 2946
    std::string s = " !";
    assert(s.compare(0, 1, {"abc", 1}) < 0);
  }
#endif

  return 0;
}
