change 'this' pointer for structs to reference type

[Denis Koroskin]

On Sun, 02 Nov 2008 10:01:24 +0300, Walter Bright  
<newshound1 at digitalmars.com> wrote:

> Andrei suggested this change, and I think it is a great idea. D ought to  
> be moving away from pointers for routine work, and this would make a lot  
> of sense.
>
> It would entail some changes to user code, mostly when dealing with the  
> opCmp and opEquals member functions. The function signatures for them  
> would be changed to opCmp(ref const S).

Could you please clarify what do you mean (I don't get it). Does this mean  
that all structs are heap-allocated by default? Or typeof(this) == S* or  
what?