Insertion operator overloading for own stream class

Question

In C++ books I meet the descriptions about how to overload insertion operators for putting data to std::ostream. But when I studied neoengine sources I met this code:

File &File::operator << ( const char *pszData )
{
    if( m_bBinary )
        do m_pkStream->write( pszData, 1 ); while( *pszData++ );
    else
        *m_pkStream << pszData;

    return( *this );
}

As you can see there is no std::ostream using. And I am not sure it correct or not by standart of C++. Where can I look for any official or serious documents or some C++ books where written that code like shown above is correct? That is to say is it to correct to overload insertion operator for own stream classes? Thanks in advance!

Answer 1

You are allowed to overload operators for user defined classes, like File .

Whether it always is a good idea, is a matter of opinion.