std::basic_fstream<CharT,Traits>::swap

Since C++11

Exchanges the state of the stream with those of other.

# Declarations

void swap( basic_fstream& other );

(since C++11)

# Parameters

# Return value

(none)

# Example

#include <fstream>
#include <iomanip>
#include <iostream>
#include <string>
 
bool create_stream(std::fstream& fs, const std::string& path)
{
    try
    {
        std::fstream ts{path, ts.trunc | ts.in | ts.out};
        if (ts.is_open())
        {
            ts.swap(fs); // stream objects are not copyable
            return true;
        }
    }
    catch (...)
    {
        std::cout << "Exception!\n";
    }
    return false;
}
 
void use_stream(std::fstream& fs)
{
    fs.seekg(0);
    std::string data;
    fs >> data;
    std::cout << "data: " << std::quoted(data) << '\n';
}
 
int main()
{
    std::fstream fs;
    std::string path = "/tmp/test_file.txt";
    if (create_stream(fs, path))
    {
        fs.write(path.c_str(), path.length());
        use_stream(fs);
    }
}

# See also