Re: Forward reference compiler error...

In article <fvhrd0$2fd$1@[EMAIL PROTECTED]
>, barcaroller@[EMAIL PROTECTED]
 says...
 
> Why does the following code cause a compiler error?
> 
> 
>     class A;  // forward reference
> 
>     class B
>     {
>         foo()
>         {
>             a = new A;
> 
>             cout << a->bar();  // compiler error here
>         }
> 
>         A* a;
>     }
> 
>     class A
>     {
>         int bar()
>         {
>             return 1;
>         }
>     }

Because when you declare (but don't define) the class, it's an 
incomplete type. You can create a pointer (or reference) to that type, 
but anything that involves _dereferencing_ the pointer (among other 
things) needs a _definition_ of the class.

For the compiler to handle something like 'a->b()', it has to have seen 
declarations for both 'a' and 'b'. Using a reference would be the same 
-- for you to use something like 'x.y()', it has to have seen 
declarations of both 'x' and 'y'.

-- 
    Later,
    Jerry.

The universe is a figment of its own imagination.