Journal Milican's Journal: Forward Declarations Tips for C++
I was recenlty on a Forward Declarations frenzy in C++, and I was having a little trouble. I recently bought a subscription to SuperNews so I could check comp.std.c++, comp.lang.c++.moderated, and other programming related newsgroups. That subscription definitely paid off because a few days later it helped point out why I was having some errors in my code. Here is an edited copy of the thread I found titled "Forward Declaration" (Subscription Required) in comp.std.c++:
---------------------------------------
>1) class a_class;
> class another_class
> {
> a_class object;
> };
This is not legal. All members must be complete.
> 2) class a_class
> class another_class
> {
> a_class* object
> }
This is perfectly OK.
> 3) class a_class;
> class another_class : public a_class
> {
> };
Again, this is not legal. Base classes must also be complete. -Richard Smith
---------------------------------------
Big thanks to Richard!
JOhn
