std::basic_filebuf<CharT,Traits>::operator= (3) - Linux Manuals

std::basic_filebuf<CharT,Traits>::operator=: std::basic_filebuf<CharT,Traits>::operator=

NAME

std::basic_filebuf<CharT,Traits>::operator= - std::basic_filebuf<CharT,Traits>::operator=

Synopsis

std::basic_filebuf& operator=( std::basic_filebuf&& rhs ); (since C++11)
std::basic_filebuf& operator=( const std::basic_filebuf& rhs ) = delete;

Assigns another basic_filebuf object.
1) First calls close() to close the associated file, then moves the contents of rhs into *this: the put and get buffers, the associated file, the locale, the openmode, the is_open flag, and any other state. After the move, rhs is not associated with a file and rhs.is_open() == false.
2) The copy assignment operator is deleted; basic_filebuf is not CopyAssignable.

Parameters

rhs - another basic_filebuf that will be moved from

Return value

*this

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'; // output

      *fin.rdbuf() = std::move(*fout.rdbuf());

      getline(fin, s);
      std::cout << s << '\n'; // empty line

      std::cout << std::boolalpha << fout.is_open() << '\n'; // prints "false"

  }