//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Copyright 2020, Intel Corporation
//
// Modified to test pmem::obj containers
//

// <string_view>

// constexpr int compare(size_type pos1, size_type n1, const charT* s) const;

#include "unittest.hpp"

#include <libpmemobj++/string_view.hpp>
#include <stdexcept>

int
sign(int x)
{
	return x > 0 ? 1 : (x < 0 ? -1 : 0);
}

template <typename CharT>
void
test1(pmem::obj::basic_string_view<CharT> sv1, size_t pos1, size_t n1,
      const CharT *s, int expected)
{
	try {
		UT_ASSERT(sign(sv1.compare(pos1, n1, s)) == sign(expected));
		UT_ASSERT(pos1 <= sv1.size());
	} catch (const std::out_of_range &) {
		UT_ASSERT(pos1 > sv1.size());
	}
}

template <typename CharT>
void
test(const CharT *s1, size_t pos1, size_t n1, const CharT *s2, int expected)
{
	typedef pmem::obj::basic_string_view<CharT> string_view_t;
	string_view_t sv1(s1);
	test1(sv1, pos1, n1, s2, expected);
}

void
test0()
{
	test("", 0, 0, "", 0);
	test("", 0, 0, "abcde", -5);
	test("", 0, 0, "abcdefghij", -10);
	test("", 0, 0, "abcdefghijklmnopqrst", -20);
	test("", 0, 1, "", 0);
	test("", 0, 1, "abcde", -5);
	test("", 0, 1, "abcdefghij", -10);
	test("", 0, 1, "abcdefghijklmnopqrst", -20);
	test("", 1, 0, "", 0);
	test("", 1, 0, "abcde", 0);
	test("", 1, 0, "abcdefghij", 0);
	test("", 1, 0, "abcdefghijklmnopqrst", 0);
	test("abcde", 0, 0, "", 0);
	test("abcde", 0, 0, "abcde", -5);
	test("abcde", 0, 0, "abcdefghij", -10);
	test("abcde", 0, 0, "abcdefghijklmnopqrst", -20);
	test("abcde", 0, 1, "", 1);
	test("abcde", 0, 1, "abcde", -4);
	test("abcde", 0, 1, "abcdefghij", -9);
	test("abcde", 0, 1, "abcdefghijklmnopqrst", -19);
	test("abcde", 0, 2, "", 2);
	test("abcde", 0, 2, "abcde", -3);
	test("abcde", 0, 2, "abcdefghij", -8);
	test("abcde", 0, 2, "abcdefghijklmnopqrst", -18);
	test("abcde", 0, 4, "", 4);
	test("abcde", 0, 4, "abcde", -1);
	test("abcde", 0, 4, "abcdefghij", -6);
	test("abcde", 0, 4, "abcdefghijklmnopqrst", -16);
	test("abcde", 0, 5, "", 5);
	test("abcde", 0, 5, "abcde", 0);
	test("abcde", 0, 5, "abcdefghij", -5);
	test("abcde", 0, 5, "abcdefghijklmnopqrst", -15);
	test("abcde", 0, 6, "", 5);
	test("abcde", 0, 6, "abcde", 0);
	test("abcde", 0, 6, "abcdefghij", -5);
	test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
	test("abcde", 1, 0, "", 0);
	test("abcde", 1, 0, "abcde", -5);
	test("abcde", 1, 0, "abcdefghij", -10);
	test("abcde", 1, 0, "abcdefghijklmnopqrst", -20);
	test("abcde", 1, 1, "", 1);
	test("abcde", 1, 1, "abcde", 1);
	test("abcde", 1, 1, "abcdefghij", 1);
	test("abcde", 1, 1, "abcdefghijklmnopqrst", 1);
	test("abcde", 1, 2, "", 2);
	test("abcde", 1, 2, "abcde", 1);
	test("abcde", 1, 2, "abcdefghij", 1);
	test("abcde", 1, 2, "abcdefghijklmnopqrst", 1);
	test("abcde", 1, 3, "", 3);
	test("abcde", 1, 3, "abcde", 1);
	test("abcde", 1, 3, "abcdefghij", 1);
	test("abcde", 1, 3, "abcdefghijklmnopqrst", 1);
	test("abcde", 1, 4, "", 4);
	test("abcde", 1, 4, "abcde", 1);
	test("abcde", 1, 4, "abcdefghij", 1);
	test("abcde", 1, 4, "abcdefghijklmnopqrst", 1);
	test("abcde", 1, 5, "", 4);
	test("abcde", 1, 5, "abcde", 1);
	test("abcde", 1, 5, "abcdefghij", 1);
	test("abcde", 1, 5, "abcdefghijklmnopqrst", 1);
	test("abcde", 2, 0, "", 0);
	test("abcde", 2, 0, "abcde", -5);
	test("abcde", 2, 0, "abcdefghij", -10);
	test("abcde", 2, 0, "abcdefghijklmnopqrst", -20);
	test("abcde", 2, 1, "", 1);
	test("abcde", 2, 1, "abcde", 2);
	test("abcde", 2, 1, "abcdefghij", 2);
	test("abcde", 2, 1, "abcdefghijklmnopqrst", 2);
	test("abcde", 2, 2, "", 2);
	test("abcde", 2, 2, "abcde", 2);
	test("abcde", 2, 2, "abcdefghij", 2);
	test("abcde", 2, 2, "abcdefghijklmnopqrst", 2);
	test("abcde", 2, 3, "", 3);
	test("abcde", 2, 3, "abcde", 2);
	test("abcde", 2, 3, "abcdefghij", 2);
	test("abcde", 2, 3, "abcdefghijklmnopqrst", 2);
	test("abcde", 2, 4, "", 3);
	test("abcde", 2, 4, "abcde", 2);
	test("abcde", 2, 4, "abcdefghij", 2);
	test("abcde", 2, 4, "abcdefghijklmnopqrst", 2);
	test("abcde", 4, 0, "", 0);
	test("abcde", 4, 0, "abcde", -5);
	test("abcde", 4, 0, "abcdefghij", -10);
	test("abcde", 4, 0, "abcdefghijklmnopqrst", -20);
	test("abcde", 4, 1, "", 1);
	test("abcde", 4, 1, "abcde", 4);
	test("abcde", 4, 1, "abcdefghij", 4);
	test("abcde", 4, 1, "abcdefghijklmnopqrst", 4);
	test("abcde", 4, 2, "", 1);
	test("abcde", 4, 2, "abcde", 4);
	test("abcde", 4, 2, "abcdefghij", 4);
	test("abcde", 4, 2, "abcdefghijklmnopqrst", 4);
	test("abcde", 5, 0, "", 0);
	test("abcde", 5, 0, "abcde", -5);
	test("abcde", 5, 0, "abcdefghij", -10);
	test("abcde", 5, 0, "abcdefghijklmnopqrst", -20);
	test("abcde", 5, 1, "", 0);
	test("abcde", 5, 1, "abcde", -5);
	test("abcde", 5, 1, "abcdefghij", -10);
	test("abcde", 5, 1, "abcdefghijklmnopqrst", -20);
}

void
test1()
{
	test("abcde", 6, 0, "", 0);
	test("abcde", 6, 0, "abcde", 0);
	test("abcde", 6, 0, "abcdefghij", 0);
	test("abcde", 6, 0, "abcdefghijklmnopqrst", 0);
	test("abcdefghij", 0, 0, "", 0);
	test("abcdefghij", 0, 0, "abcde", -5);
	test("abcdefghij", 0, 0, "abcdefghij", -10);
	test("abcdefghij", 0, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 0, 1, "", 1);
	test("abcdefghij", 0, 1, "abcde", -4);
	test("abcdefghij", 0, 1, "abcdefghij", -9);
	test("abcdefghij", 0, 1, "abcdefghijklmnopqrst", -19);
	test("abcdefghij", 0, 5, "", 5);
	test("abcdefghij", 0, 5, "abcde", 0);
	test("abcdefghij", 0, 5, "abcdefghij", -5);
	test("abcdefghij", 0, 5, "abcdefghijklmnopqrst", -15);
	test("abcdefghij", 0, 9, "", 9);
	test("abcdefghij", 0, 9, "abcde", 4);
	test("abcdefghij", 0, 9, "abcdefghij", -1);
	test("abcdefghij", 0, 9, "abcdefghijklmnopqrst", -11);
	test("abcdefghij", 0, 10, "", 10);
	test("abcdefghij", 0, 10, "abcde", 5);
	test("abcdefghij", 0, 10, "abcdefghij", 0);
	test("abcdefghij", 0, 10, "abcdefghijklmnopqrst", -10);
	test("abcdefghij", 0, 11, "", 10);
	test("abcdefghij", 0, 11, "abcde", 5);
	test("abcdefghij", 0, 11, "abcdefghij", 0);
	test("abcdefghij", 0, 11, "abcdefghijklmnopqrst", -10);
	test("abcdefghij", 1, 0, "", 0);
	test("abcdefghij", 1, 0, "abcde", -5);
	test("abcdefghij", 1, 0, "abcdefghij", -10);
	test("abcdefghij", 1, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 1, 1, "", 1);
	test("abcdefghij", 1, 1, "abcde", 1);
	test("abcdefghij", 1, 1, "abcdefghij", 1);
	test("abcdefghij", 1, 1, "abcdefghijklmnopqrst", 1);
	test("abcdefghij", 1, 4, "", 4);
	test("abcdefghij", 1, 4, "abcde", 1);
	test("abcdefghij", 1, 4, "abcdefghij", 1);
	test("abcdefghij", 1, 4, "abcdefghijklmnopqrst", 1);
	test("abcdefghij", 1, 8, "", 8);
	test("abcdefghij", 1, 8, "abcde", 1);
	test("abcdefghij", 1, 8, "abcdefghij", 1);
	test("abcdefghij", 1, 8, "abcdefghijklmnopqrst", 1);
	test("abcdefghij", 1, 9, "", 9);
	test("abcdefghij", 1, 9, "abcde", 1);
	test("abcdefghij", 1, 9, "abcdefghij", 1);
	test("abcdefghij", 1, 9, "abcdefghijklmnopqrst", 1);
	test("abcdefghij", 1, 10, "", 9);
	test("abcdefghij", 1, 10, "abcde", 1);
	test("abcdefghij", 1, 10, "abcdefghij", 1);
	test("abcdefghij", 1, 10, "abcdefghijklmnopqrst", 1);
	test("abcdefghij", 5, 0, "", 0);
	test("abcdefghij", 5, 0, "abcde", -5);
	test("abcdefghij", 5, 0, "abcdefghij", -10);
	test("abcdefghij", 5, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 5, 1, "", 1);
	test("abcdefghij", 5, 1, "abcde", 5);
	test("abcdefghij", 5, 1, "abcdefghij", 5);
	test("abcdefghij", 5, 1, "abcdefghijklmnopqrst", 5);
	test("abcdefghij", 5, 2, "", 2);
	test("abcdefghij", 5, 2, "abcde", 5);
	test("abcdefghij", 5, 2, "abcdefghij", 5);
	test("abcdefghij", 5, 2, "abcdefghijklmnopqrst", 5);
	test("abcdefghij", 5, 4, "", 4);
	test("abcdefghij", 5, 4, "abcde", 5);
	test("abcdefghij", 5, 4, "abcdefghij", 5);
	test("abcdefghij", 5, 4, "abcdefghijklmnopqrst", 5);
	test("abcdefghij", 5, 5, "", 5);
	test("abcdefghij", 5, 5, "abcde", 5);
	test("abcdefghij", 5, 5, "abcdefghij", 5);
	test("abcdefghij", 5, 5, "abcdefghijklmnopqrst", 5);
	test("abcdefghij", 5, 6, "", 5);
	test("abcdefghij", 5, 6, "abcde", 5);
	test("abcdefghij", 5, 6, "abcdefghij", 5);
	test("abcdefghij", 5, 6, "abcdefghijklmnopqrst", 5);
	test("abcdefghij", 9, 0, "", 0);
	test("abcdefghij", 9, 0, "abcde", -5);
	test("abcdefghij", 9, 0, "abcdefghij", -10);
	test("abcdefghij", 9, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 9, 1, "", 1);
	test("abcdefghij", 9, 1, "abcde", 9);
	test("abcdefghij", 9, 1, "abcdefghij", 9);
	test("abcdefghij", 9, 1, "abcdefghijklmnopqrst", 9);
	test("abcdefghij", 9, 2, "", 1);
	test("abcdefghij", 9, 2, "abcde", 9);
	test("abcdefghij", 9, 2, "abcdefghij", 9);
	test("abcdefghij", 9, 2, "abcdefghijklmnopqrst", 9);
	test("abcdefghij", 10, 0, "", 0);
	test("abcdefghij", 10, 0, "abcde", -5);
	test("abcdefghij", 10, 0, "abcdefghij", -10);
	test("abcdefghij", 10, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 10, 1, "", 0);
	test("abcdefghij", 10, 1, "abcde", -5);
	test("abcdefghij", 10, 1, "abcdefghij", -10);
	test("abcdefghij", 10, 1, "abcdefghijklmnopqrst", -20);
	test("abcdefghij", 11, 0, "", 0);
	test("abcdefghij", 11, 0, "abcde", 0);
	test("abcdefghij", 11, 0, "abcdefghij", 0);
	test("abcdefghij", 11, 0, "abcdefghijklmnopqrst", 0);
}

void
test2()
{
	test("abcdefghijklmnopqrst", 0, 0, "", 0);
	test("abcdefghijklmnopqrst", 0, 0, "abcde", -5);
	test("abcdefghijklmnopqrst", 0, 0, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 0, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 0, 1, "", 1);
	test("abcdefghijklmnopqrst", 0, 1, "abcde", -4);
	test("abcdefghijklmnopqrst", 0, 1, "abcdefghij", -9);
	test("abcdefghijklmnopqrst", 0, 1, "abcdefghijklmnopqrst", -19);
	test("abcdefghijklmnopqrst", 0, 10, "", 10);
	test("abcdefghijklmnopqrst", 0, 10, "abcde", 5);
	test("abcdefghijklmnopqrst", 0, 10, "abcdefghij", 0);
	test("abcdefghijklmnopqrst", 0, 10, "abcdefghijklmnopqrst", -10);
	test("abcdefghijklmnopqrst", 0, 19, "", 19);
	test("abcdefghijklmnopqrst", 0, 19, "abcde", 14);
	test("abcdefghijklmnopqrst", 0, 19, "abcdefghij", 9);
	test("abcdefghijklmnopqrst", 0, 19, "abcdefghijklmnopqrst", -1);
	test("abcdefghijklmnopqrst", 0, 20, "", 20);
	test("abcdefghijklmnopqrst", 0, 20, "abcde", 15);
	test("abcdefghijklmnopqrst", 0, 20, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 0, 20, "abcdefghijklmnopqrst", 0);
	test("abcdefghijklmnopqrst", 0, 21, "", 20);
	test("abcdefghijklmnopqrst", 0, 21, "abcde", 15);
	test("abcdefghijklmnopqrst", 0, 21, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 0, 21, "abcdefghijklmnopqrst", 0);
	test("abcdefghijklmnopqrst", 1, 0, "", 0);
	test("abcdefghijklmnopqrst", 1, 0, "abcde", -5);
	test("abcdefghijklmnopqrst", 1, 0, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 1, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 1, 1, "", 1);
	test("abcdefghijklmnopqrst", 1, 1, "abcde", 1);
	test("abcdefghijklmnopqrst", 1, 1, "abcdefghij", 1);
	test("abcdefghijklmnopqrst", 1, 1, "abcdefghijklmnopqrst", 1);
	test("abcdefghijklmnopqrst", 1, 9, "", 9);
	test("abcdefghijklmnopqrst", 1, 9, "abcde", 1);
	test("abcdefghijklmnopqrst", 1, 9, "abcdefghij", 1);
	test("abcdefghijklmnopqrst", 1, 9, "abcdefghijklmnopqrst", 1);
	test("abcdefghijklmnopqrst", 1, 18, "", 18);
	test("abcdefghijklmnopqrst", 1, 18, "abcde", 1);
	test("abcdefghijklmnopqrst", 1, 18, "abcdefghij", 1);
	test("abcdefghijklmnopqrst", 1, 18, "abcdefghijklmnopqrst", 1);
	test("abcdefghijklmnopqrst", 1, 19, "", 19);
	test("abcdefghijklmnopqrst", 1, 19, "abcde", 1);
	test("abcdefghijklmnopqrst", 1, 19, "abcdefghij", 1);
	test("abcdefghijklmnopqrst", 1, 19, "abcdefghijklmnopqrst", 1);
	test("abcdefghijklmnopqrst", 1, 20, "", 19);
	test("abcdefghijklmnopqrst", 1, 20, "abcde", 1);
	test("abcdefghijklmnopqrst", 1, 20, "abcdefghij", 1);
	test("abcdefghijklmnopqrst", 1, 20, "abcdefghijklmnopqrst", 1);
	test("abcdefghijklmnopqrst", 10, 0, "", 0);
	test("abcdefghijklmnopqrst", 10, 0, "abcde", -5);
	test("abcdefghijklmnopqrst", 10, 0, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 10, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 10, 1, "", 1);
	test("abcdefghijklmnopqrst", 10, 1, "abcde", 10);
	test("abcdefghijklmnopqrst", 10, 1, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 10, 1, "abcdefghijklmnopqrst", 10);
	test("abcdefghijklmnopqrst", 10, 5, "", 5);
	test("abcdefghijklmnopqrst", 10, 5, "abcde", 10);
	test("abcdefghijklmnopqrst", 10, 5, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 10, 5, "abcdefghijklmnopqrst", 10);
	test("abcdefghijklmnopqrst", 10, 9, "", 9);
	test("abcdefghijklmnopqrst", 10, 9, "abcde", 10);
	test("abcdefghijklmnopqrst", 10, 9, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 10, 9, "abcdefghijklmnopqrst", 10);
	test("abcdefghijklmnopqrst", 10, 10, "", 10);
	test("abcdefghijklmnopqrst", 10, 10, "abcde", 10);
	test("abcdefghijklmnopqrst", 10, 10, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 10, 10, "abcdefghijklmnopqrst", 10);
	test("abcdefghijklmnopqrst", 10, 11, "", 10);
	test("abcdefghijklmnopqrst", 10, 11, "abcde", 10);
	test("abcdefghijklmnopqrst", 10, 11, "abcdefghij", 10);
	test("abcdefghijklmnopqrst", 10, 11, "abcdefghijklmnopqrst", 10);
	test("abcdefghijklmnopqrst", 19, 0, "", 0);
	test("abcdefghijklmnopqrst", 19, 0, "abcde", -5);
	test("abcdefghijklmnopqrst", 19, 0, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 19, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 19, 1, "", 1);
	test("abcdefghijklmnopqrst", 19, 1, "abcde", 19);
	test("abcdefghijklmnopqrst", 19, 1, "abcdefghij", 19);
	test("abcdefghijklmnopqrst", 19, 1, "abcdefghijklmnopqrst", 19);
	test("abcdefghijklmnopqrst", 19, 2, "", 1);
	test("abcdefghijklmnopqrst", 19, 2, "abcde", 19);
	test("abcdefghijklmnopqrst", 19, 2, "abcdefghij", 19);
	test("abcdefghijklmnopqrst", 19, 2, "abcdefghijklmnopqrst", 19);
	test("abcdefghijklmnopqrst", 20, 0, "", 0);
	test("abcdefghijklmnopqrst", 20, 0, "abcde", -5);
	test("abcdefghijklmnopqrst", 20, 0, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 20, 0, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 20, 1, "", 0);
	test("abcdefghijklmnopqrst", 20, 1, "abcde", -5);
	test("abcdefghijklmnopqrst", 20, 1, "abcdefghij", -10);
	test("abcdefghijklmnopqrst", 20, 1, "abcdefghijklmnopqrst", -20);
	test("abcdefghijklmnopqrst", 21, 0, "", 0);
	test("abcdefghijklmnopqrst", 21, 0, "abcde", 0);
	test("abcdefghijklmnopqrst", 21, 0, "abcdefghij", 0);
	test("abcdefghijklmnopqrst", 21, 0, "abcdefghijklmnopqrst", 0);
}

static void
run()
{
	test0();
	test1();
	test2();

	{
		test("", 0, 0, "", 0);
		test("", 0, 0, "abcde", -5);
		test("", 0, 0, "abcdefghij", -10);
		test("", 0, 0, "abcdefghijklmnopqrst", -20);
		test("abcde", 0, 2, "", 5);
		test("abcde", 0, 6, "abcde", 0);
		test("abcde", 0, 6, "abcdefghij", -5);
		test("abcde", 0, 6, "abcdefghijklmnopqrst", -15);
		test("abcdefghij", 3, 3, "", 10);
		test("abcdefghij", 3, 3, "abcde", 5);
		test("abcdefghij", 3, 3, "def", 0);
		test("abcdefghij", 0, 4, "abcdefghijklmnopqrst", -10);
		test("abcdefghijklmnopqrst", 5, 5, "", 20);
		test("abcdefghijklmnopqrst", 0, 8, "abcde", 15);
		test("abcdefghijklmnopqrst", 0, 12, "abcdefghij", 10);
		test("abcdefghijklmnopqrst", 0, static_cast<size_t>(-1),
		     "abcdefghijklmnopqrst", 0);
	}

	{
		test(L"", 0, 0, L"", 0);
		test(L"", 0, 0, L"abcde", -5);
		test(L"", 0, 0, L"abcdefghij", -10);
		test(L"", 0, 0, L"abcdefghijklmnopqrst", -20);
		test(L"abcde", 0, 2, L"", 5);
		test(L"abcde", 0, 6, L"abcde", 0);
		test(L"abcde", 0, 6, L"abcdefghij", -5);
		test(L"abcde", 0, 6, L"abcdefghijklmnopqrst", -15);
		test(L"abcdefghij", 3, 3, L"", 10);
		test(L"abcdefghij", 3, 3, L"abcde", 5);
		test(L"abcdefghij", 3, 3, L"def", 0);
		test(L"abcdefghij", 0, 4, L"abcdefghijklmnopqrst", -10);
		test(L"abcdefghijklmnopqrst", 5, 5, L"", 20);
		test(L"abcdefghijklmnopqrst", 0, 8, L"abcde", 15);
		test(L"abcdefghijklmnopqrst", 0, 12, L"abcdefghij", 10);
		test(L"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1),
		     L"abcdefghijklmnopqrst", 0);
	}

	{
		test(U"", 0, 0, U"", 0);
		test(U"", 0, 0, U"abcde", -5);
		test(U"", 0, 0, U"abcdefghij", -10);
		test(U"", 0, 0, U"abcdefghijklmnopqrst", -20);
		test(U"abcde", 0, 2, U"", 5);
		test(U"abcde", 0, 6, U"abcde", 0);
		test(U"abcde", 0, 6, U"abcdefghij", -5);
		test(U"abcde", 0, 6, U"abcdefghijklmnopqrst", -15);
		test(U"abcdefghij", 3, 3, U"", 10);
		test(U"abcdefghij", 3, 3, U"abcde", 5);
		test(U"abcdefghij", 3, 3, U"def", 0);
		test(U"abcdefghij", 0, 4, U"abcdefghijklmnopqrst", -10);
		test(U"abcdefghijklmnopqrst", 5, 5, U"", 20);
		test(U"abcdefghijklmnopqrst", 0, 8, U"abcde", 15);
		test(U"abcdefghijklmnopqrst", 0, 12, U"abcdefghij", 10);
		test(U"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1),
		     U"abcdefghijklmnopqrst", 0);
	}

	{
		test(u"", 0, 0, u"", 0);
		test(u"", 0, 0, u"abcde", -5);
		test(u"", 0, 0, u"abcdefghij", -10);
		test(u"", 0, 0, u"abcdefghijklmnopqrst", -20);
		test(u"abcde", 0, 2, u"", 5);
		test(u"abcde", 0, 6, u"abcde", 0);
		test(u"abcde", 0, 6, u"abcdefghij", -5);
		test(u"abcde", 0, 6, u"abcdefghijklmnopqrst", -15);
		test(u"abcdefghij", 3, 3, u"", 10);
		test(u"abcdefghij", 3, 3, u"abcde", 5);
		test(u"abcdefghij", 3, 3, u"def", 0);
		test(u"abcdefghij", 0, 4, u"abcdefghijklmnopqrst", -10);
		test(u"abcdefghijklmnopqrst", 5, 5, u"", 20);
		test(u"abcdefghijklmnopqrst", 0, 8, u"abcde", 15);
		test(u"abcdefghijklmnopqrst", 0, 12, u"abcdefghij", 10);
		test(u"abcdefghijklmnopqrst", 0, static_cast<size_t>(-1),
		     u"abcdefghijklmnopqrst", 0);
	}
}

int
main(int argc, char *argv[])
{
	return run_test([&] { run(); });
}
