std::basic_istream<CharT,Traits>::swap (3) - Linux Manuals

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


std::basic_istream<CharT,Traits>::swap - std::basic_istream<CharT,Traits>::swap


protected: (since C++11)
void swap(basic_istream& rhs);

Calls basic_ios::swap(rhs) to swap all data members of the base class except for rdbuf(), and swaps the values of the gcount() counters between *this and rhs. This swap function is protected: it is called by the swap functions of the swappable input stream classes std::basic_ifstream and std::basic_istringstream, which know how to correctly swap the associated streambuffers.


rhs - different basic_istream object of the same type to swap with


// Run this code

  #include <sstream>
  #include <iostream>
  #include <utility>
  int main()
      std::istringstream s1("hello");
      std::istringstream s2("bye");

      s1.swap(s2); // OK, istringstream has a public swap()
      std::swap(s1, s2); // OK, calls s1.swap(s2)
  // std::cin.swap(s2); // ERROR: swap is a protected member

      std::cout << s1.rdbuf();