< cpp‎ | io‎ | basic filebuf
void swap( std::basic_filebuf& rhs );
(since C++11)

Swaps the state and the contents of *this and rhs.


[edit] Parameters

rhs - another basic_filebuf

[edit] Return value


[edit] Notes

This function is called automatically when swapping std::fstream objects, it is rarely necessary to call it directly.

[edit] Example

#include <fstream>
#include <string>
#include <iostream>
int main()
    std::ifstream fin(""); // read-only
    std::ofstream fout("test.out"); // write-only
    std::string s;
    getline(fin, s);
    std::cout << s << '\n'; // outputs the first line of
    fin.rdbuf()->swap(*fout.rdbuf()); //swap the underlying buffers
    getline(fin, s); // fails: cannot read from a write-only filebuf
    std::cout << s << '\n'; // prints empty line

[edit] See also

assigns a basic_filebuf object
(public member function)
specializes the std::swap algorithm
(function template)
swaps two file streams
(public member function of std::basic_fstream)