Newbie initial comments on D language - scope

[Walter Bright]

Edward Diener wrote:
> The idea in my mind is essentially that 'scope' classes automatically 
> define an object that, when used exactly as an normal GC object, 
> automatically calls the destructor of the object just as soon as the 
> last reference to it goes out of scope. In this sense the user neither 
> know or cares whether the object encapsulates a resource or not and uses 
> an object of such a class just as he would use any other GC object. 
> Similarly the user can force an object to be a 'scope' object through 
> the second syntax give above, but from then on he treats the object just 
> as he would any other GC object.

The problem is:
	scope C c;
	C d;
	d = c;
and now d is no longer properly ref-counted. The 'scopeness' of an 
object must therefore be part of its type. The assignment d=c would have 
to be illegal.


> Please take a look at atomic operations, which I am sure you already 
> know about. I believe boost::shared_ptr<T> in its latest incarnation is 
>  using it to increment and decrement the reference count without the 
> usual time penalty which you mention.

There has been a lot of work done improving atomic operations. That's 
one reason for making it a library feature - the library stuff can be 
improved without having to change the compiler.