libcxx/test/input.output/file.streams/fstreams/fstream.assign/member_swap.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <fstream>

// template <class charT, class traits = char_traits<charT> >
// class basic_fstream

// void swap(basic_fstream& rhs);

#include <fstream>
#include <cassert>

int main()
{
    {
        std::fstream fs1("test1.dat", std::ios_base::in | std::ios_base::out
                                                        | std::ios_base::trunc);
        std::fstream fs2("test2.dat", std::ios_base::in | std::ios_base::out
                                                        | std::ios_base::trunc);
        fs1 << 1 << ' ' << 2;
        fs2 << 2 << ' ' << 1;
        fs1.seekg(0);
        fs1.swap(fs2);
        fs1.seekg(0);
        int i;
        fs1 >> i;
        assert(i == 2);
        fs1 >> i;
        assert(i == 1);
        i = 0;
        fs2 >> i;
        assert(i == 1);
        fs2 >> i;
        assert(i == 2);
    }
    std::remove("test1.dat");
    std::remove("test2.dat");
    {
        std::wfstream fs1("test1.dat", std::ios_base::in | std::ios_base::out
                                                         | std::ios_base::trunc);
        std::wfstream fs2("test2.dat", std::ios_base::in | std::ios_base::out
                                                         | std::ios_base::trunc);
        fs1 << 1 << ' ' << 2;
        fs2 << 2 << ' ' << 1;
        fs1.seekg(0);
        fs1.swap(fs2);
        fs1.seekg(0);
        int i;
        fs1 >> i;
        assert(i == 2);
        fs1 >> i;
        assert(i == 1);
        i = 0;
        fs2 >> i;
        assert(i == 1);
        fs2 >> i;
        assert(i == 2);
    }
    std::remove("test1.dat");
    std::remove("test2.dat");
}