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

// <iterator>

// istreambuf_iterator

// template <class charT, class traits>
//   bool operator!=(const istreambuf_iterator<charT,traits>& a,
//                   const istreambuf_iterator<charT,traits>& b);

#include <iterator>
#include <sstream>
#include <cassert>

int main(int, char**)
{
    {
        std::istringstream inf1("abc");
        std::istringstream inf2("def");
        std::istreambuf_iterator<char> i1(inf1);
        std::istreambuf_iterator<char> i2(inf2);
        std::istreambuf_iterator<char> i3;
        std::istreambuf_iterator<char> i4;
        std::istreambuf_iterator<char> i5(nullptr);

        assert(!(i1 != i1));
        assert(!(i1 != i2));
        assert( (i1 != i3));
        assert( (i1 != i4));
        assert( (i1 != i5));

        assert(!(i2 != i1));
        assert(!(i2 != i2));
        assert( (i2 != i3));
        assert( (i2 != i4));
        assert( (i2 != i5));

        assert( (i3 != i1));
        assert( (i3 != i2));
        assert(!(i3 != i3));
        assert(!(i3 != i4));
        assert(!(i3 != i5));

        assert( (i4 != i1));
        assert( (i4 != i2));
        assert(!(i4 != i3));
        assert(!(i4 != i4));
        assert(!(i4 != i5));

        assert( (i5 != i1));
        assert( (i5 != i2));
        assert(!(i5 != i3));
        assert(!(i5 != i4));
        assert(!(i5 != i5));
    }
    {
        std::wistringstream inf1(L"abc");
        std::wistringstream inf2(L"def");
        std::istreambuf_iterator<wchar_t> i1(inf1);
        std::istreambuf_iterator<wchar_t> i2(inf2);
        std::istreambuf_iterator<wchar_t> i3;
        std::istreambuf_iterator<wchar_t> i4;
        std::istreambuf_iterator<wchar_t> i5(nullptr);

        assert(!(i1 != i1));
        assert(!(i1 != i2));
        assert( (i1 != i3));
        assert( (i1 != i4));
        assert( (i1 != i5));

        assert(!(i2 != i1));
        assert(!(i2 != i2));
        assert( (i2 != i3));
        assert( (i2 != i4));
        assert( (i2 != i5));

        assert( (i3 != i1));
        assert( (i3 != i2));
        assert(!(i3 != i3));
        assert(!(i3 != i4));
        assert(!(i3 != i5));

        assert( (i4 != i1));
        assert( (i4 != i2));
        assert(!(i4 != i3));
        assert(!(i4 != i4));
        assert(!(i4 != i5));

        assert( (i5 != i1));
        assert( (i5 != i2));
        assert(!(i5 != i3));
        assert(!(i5 != i4));
        assert(!(i5 != i5));
    }

  return 0;
}