Semantics of shared

[Jason House]

Robert Jacques Wrote:

> On Thu, 14 May 2009 02:13:37 -0400, Walter Bright  
> <newshound1 at digitalmars.com> wrote:
> 
> > Robert Jacques wrote:
> >> I agree for POD, but what classes where the synchronization is  
> >> encapsulated behind a virtual function call?
> >
> > synchronization can make a shared reference "tail shared".
> 
> I agree, but that doesn't seem answer my question. Put another way, if I  
> have an interface I which is implemented by both a thread local class L  
> and a shared class S, then does some function F need to know about whether  
> the implementor of I is S or L?

Shared data needs fundamentally different handling than thread local data. I expect "shared I" and "__thread I" to be handled differently. You can't store an S where an L is expected... It can break code.
 
> P.S. There will obviously be some interfaces S can't implement, but that a  
> separate issue.
> 
> >> Also, does this mean 'scope' as a type is going away?

Of course not. Scope storage class will remain.
> > Scope never was a type, it's a storage class.
> 
> Sorry for the confusion of terminology. However, you talk blog about using  
> the 'scope' keyword to support escape analysis, ettc. i.e. 'scope' would  
> become the 'const' of the shared-thread local-stack storage type system.  
> Is this still the plan?