Scope storage class

[Sergey Gromov]

Mon, 01 Dec 2008 10:26:31 -0700, Russell Lewis wrote:

> The thing to remember is that "scope" is *not* transitive.  Scope limits 
> the most shallow reference, *not* not anything deeper.  It is perfectly 
> valid to have a scope pointer to a non-scope thing.  The point of scope 
> is to enforce that the pointer cannot escape; it does not say anything 
> about whether the pointed-to object escapes or not.
> 
> The point then, is that you can create a non-scope object, and assign it 
> to a scope pointer.  When you do something like:
> 
> BEGIN CODE
> 	scope <type> a;
> 	a = <allocate thing>;
> END CODE
> 
> ...you are doing exactly that.
> 
> (At least, that's how I think it ought to work.)

http://www.digitalmars.com/d/1.0/attribute.html#scope

Originally, the scope keyword wasn't about escaping, it was about memory
management.  The code

  scope C c = new C;

was a sugar for

  C c =new C;
  scope(exit) delete c;
  
The spec says, "Assignment to a scope, other than initialization, is not
allowed."  Therefore your example is illegal.  I think the fact that DMD
accepts such a code is a bug.  I'll file a bug report.