Re: Total Newbie Backward Compat Question

On Mar 10, 8:15 am, "Chris ( Val )" <chris...@[EMAIL PROTECTED]
> wrote:
> On Mar 10, 11:05 pm, Richard Heathfield <r...@[EMAIL PROTECTED]
> wrote:
>
> > Crazy c said:
>
> > <snip>
>
> > > Are you saying that if I use std::cout, I do not have to overload
> > > operator <<?
>
> > If you want std::cout to be able to display objects of your own
definition
> > (as opposed to vanilla types such as int, double, etc), then you need
to
> > overload << within your class.
>
> The overload does not necessarily need to be "within" the class.
>


Yes and No.

In the manner that Richard said, it cannot be implemented within the
class.  The operator << is a member function on the cout object, so it
does not make sense to provide a << operator that pur****tedly writes
to
ostream -- it will never be called by a statement such as cout <<
MyObj;

However, rather than use member functions that are essentially
accessor
functions within the global overload of operator << for your class,
one
could implement a member function such as print() that is called from
this
global overload.  That way, there is a member function that you, as
the
author of the class, control how your objects get output to a stream.

More about this at http://www.gotw.ca/gotw/004.htm

- Anand