DIP69 - Implement scope for escape proof references

[Walter Bright via Digitalmars-d]

http://wiki.dlang.org/DIP69

Despite its length, this is a fairly simple proposal. It adds the missing 
semantics for the 'scope' storage class in order to make it possible to pass a 
reference to a function without it being possible for it to escape.

This, among other things, makes a ref counting type practical. It also makes it 
more practical to use other storage allocation schemes than garbage collection.

It does not make scope into a type constructor, nor a general type-annotation 
system.

It does not provide an ownership system, though it would complement one.