Rationale for classes as reference types

[Steven Schveighoffer]

"A Lahav" wrote
> Can anyone please explain the design rationale for classes being reference 
> types exclusively?
>
> I ask this because I really like my classes to be allocated on the stack 
> or be value-type data members, the performance boost you get eliminiting 
> all these unnecessary heap operations is entirely not neglible.
>
> Otherwise I'll have a real problem considering D for my own use...

Because of many reasons Walter has described in the past.  The one that 
sticks out to me is the chopping effect (don't know if this is the right 
term).  Let's say a function returns a non-reference class instance, and 
your function returns a derived instance.  The return value chops off the 
derived stuff.

I like the way classes are always references.  But there is a way to ensure 
a class gets allocated on the stack:

scope c = new MyClass(...);

This will allocate the class on the stack.  Be sure not to return a 
reference to it later though!

Another possibility is to use structs instead, which do not have 
inheritance, and so will not cause the chopping effect.

-Steve