ios::operator void*


public member function
operator void * ( ) const;

Convert to pointer

A stream object derived from ios can be casted to a pointer. This pointer is a null pointer if either one of the error flags (failbit or badbit) is set, otherwise it is a non-zero pointer.

The pointer returned is not intended to be referenced, it just indicates success when none of the error flags are set.

Parameters

none

Return Value

null pointer if either failbit or badbit is set.
A non-null pointer otherwise.

Example

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// ios, casting to pointer
#include <iostream>
#include <fstream>
using namespace std;

int main () {
  ifstream is;
  is.open ("test.txt");
  if ( (void*)is == 0)
    cerr << "Error opening 'test.txt'\n";
  return 0;
}


Basic template member declaration

( basic_ios<charT,traits> )
  
operator void * () const;


See also

ios::fail Check if either failbit or badbit is set (public member function)
ios::operator! Evaluate stream object (public member function)