On Thursday, July 26, 2012 21:09:09 Chad J wrote:
> I keep hearing that scope variables are going away. I missed the
> discussion on it. Why is this happening?
>
> When I read about this, I have these in mind:
>
> void someFunc()
> {
> // foo is very likely to get stack allocated
> scope foo = new SomeClass();
> foo.use();
> // ~foo is called.
> }
It's inherently unsafe. What happens if you returned a reference to foo from
someFunc? Or if you assigned a reference to foo to anything and then tried to
use it after someFunc has returned? You get undefined behavior, because foo
doesn't exist anymore. If you really need foo to be on the stack, then maybe
you should make it a struct. However, if you really do need scope for some
reason, then you can use std.typecons.scoped, and it'll do the same thing.
scope on local variables is going away for pretty much the same reason that
delete is. They're unsafe, and the fact that they're in the core language
encourages their use. So, they're being removed and put into the standard
library instead.
- Jonathan M Davis
