C++

Reference

<fstream>

ifstream

public member function
<fstream>

std::ifstream::swap

void swap (ifstream& x);
Swap internals
Exchanges all internal data between x and *this.

Internally, the function calls istream::swap and then calls the member swap of the associated filebuf object.

Parameters

x
Another ifstream object.

Return Value

none

Example

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// swapping ifstream objects
#include <iostream>     // std::cout
#include <fstream>      // std::ifstream

int main () {
  std::ifstream foo;
  std::ifstream bar ("test.txt");

  foo.swap(bar);

  char c = foo.get();

  while (foo.good()) {
    std::cout << c;
    c = foo.get();
  }

  foo.close();

  return 0;
}

Data races

Modifies both stream objects (*this and x).

Exception safety

No-throw guarantee: this member function never throws exceptions.

See also

ifstream::operator=
Move assignment (public member function)
istream::swap
Swap internals (protected member function)