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std::basic_filebuf::swap(3) C++ Standard Libary std::basic_filebuf::swap(3)

NAME

std::basic_filebuf::swap - std::basic_filebuf::swap

Synopsis


void swap( std::basic_filebuf& rhs ); (since C++11)


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

Parameters


rhs - another basic_filebuf

Return value


(none)

Notes


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

Example

// Run this code


#include <fstream>
#include <string>
#include <iostream>


int main()
{
std::ifstream fin("test.in"); // read-only
std::ofstream fout("test.out"); // write-only


std::string s;
getline(fin, s);
std::cout << s << '\n'; // outputs the first line of test.in


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
}

See also


operator= assigns a basic_filebuf object
(C++11) (public member function)
std::swap(std::basic_filebuf) specializes the std::swap algorithm
(C++11) (function template)
swap swaps two file streams
(C++11) (public member function of
std::basic_fstream<CharT,Traits>)

2022.07.31 http://cppreference.com