test/std/input.output/file.streams/fstreams/ofstream.assign/nonmember_swap.pass.cpp

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

// <fstream>

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

// template <class charT, class traits>
//   void swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);

#include <fstream>
#include <utility>
#include <cassert>
#include "test_macros.h"
#include "platform_support.h"

std::pair<std::string, std::string> get_temp_file_names() {
  std::pair<std::string, std::string> names;
  names.first = get_temp_file_name();

  // Create the file so the next call to `get_temp_file_name()` doesn't
  // return the same file.
  std::FILE *fd1 = std::fopen(names.first.c_str(), "w");

  names.second = get_temp_file_name();
  assert(names.first != names.second);

  std::fclose(fd1);
  std::remove(names.first.c_str());

  return names;
}

int main(int, char**)
{
    std::pair<std::string, std::string> temp_files = get_temp_file_names();
    std::string& temp1 = temp_files.first;
    std::string& temp2 = temp_files.second;
    assert(temp1 != temp2);
    {
        std::ofstream fs1(temp1.c_str());
        std::ofstream fs2(temp2.c_str());
        fs1 << 3.25;
        fs2 << 4.5;
        swap(fs1, fs2);
        fs1 << ' ' << 3.25;
        fs2 << ' ' << 4.5;
    }
    {
        std::ifstream fs(temp1.c_str());
        double x = 0;
        fs >> x;
        assert(x == 3.25);
        fs >> x;
        assert(x == 4.5);
    }
    std::remove(temp1.c_str());
    {
        std::ifstream fs(temp2.c_str());
        double x = 0;
        fs >> x;
        assert(x == 4.5);
        fs >> x;
        assert(x == 3.25);
    }
    std::remove(temp2.c_str());

#ifndef TEST_HAS_NO_WIDE_CHARACTERS
    {
        std::wofstream fs1(temp1.c_str());
        std::wofstream fs2(temp2.c_str());
        fs1 << 3.25;
        fs2 << 4.5;
        swap(fs1, fs2);
        fs1 << ' ' << 3.25;
        fs2 << ' ' << 4.5;
    }
    {
        std::wifstream fs(temp1.c_str());
        double x = 0;
        fs >> x;
        assert(x == 3.25);
        fs >> x;
        assert(x == 4.5);
    }
    std::remove(temp1.c_str());
    {
        std::wifstream fs(temp2.c_str());
        double x = 0;
        fs >> x;
        assert(x == 4.5);
        fs >> x;
        assert(x == 3.25);
    }
    std::remove(temp2.c_str());
#endif

  return 0;
}