[dmd-concurrency] is shared going to be a type modifier?

[Andrei Alexandrescu]

Steve Schveighoffer wrote:
> ----- Original Message ----
> 
>> From: Andrei Alexandrescu <andrei at erdani.com> Yes, shared is a type
>> qualifier. For the most part it behaves like immutable. Note that
>> you can define an immutable member of an otherwise mutable type.
>> 
> 
> Right, but this to me makes sense -- I want to define something that
> is always immutable.  A piece of data becomes immutable the second
> you declare it is.
> 
> But when I mark a class member shared, it does not truly become
> shared by declaring it that way -- allocating an instance of such a
> class does not make its shared members available to other threads.
> Compare that to a global, which is immediately shared.  I think this
> is going to have to be really explained well.  As a member storage
> class, shared really should be called "shareable".
> 
> Despite that, I think I get it.  The address to a shared member could
> be passed to other threads, even though the full object is not, is
> that correct?

Of course, plus the more frequent case is:

class SList { ... }
struct A { int x; shared SList lst; }


Andrei