From: Thore Karlsen (sid_at_[hidden])
Date: 2005-09-22 15:20:04
On Thu, 22 Sep 2005 15:54:31 -0400, Jason Stewart <jstewart_at_[hidden]>
wrote:
>> > By the way, that might work well for smart
>> > pointers; why don't shared_ptr and friends use this idiom?
>>Maybe because it allows more than a literal zero?
>I personally like the guard/dismiss names, they are reminiscent of
>commands you would give a real guard.
>
>However, maybe using the shared_ptr semantics would work. I.e. if you
>can create a guard that is "uninitialized" and then reset it later to
>an active guard.
>
>{
> scope_guard g;
>
> if (some condition)
> {
> g = scope_guard(my_undo_function);
> // do something here
> }
>
> if (some other condition)
> {
> // we changed our mind, dismiss it.
> g = scope_guard;
>
> // or ...
> // g.dismiss();
> // g.reset(); // like shared_ptr
> }
>}
>
>It seems to me that is as easy to read as having an explicit "guard"
>or "activate" command is. I confess though that I didn't follow the
>early discussion closely so I apologize is this has been discussed already.
I don't think this will work well, because the guard could be fairly
complex. I'd hate to have several identical multi-line guard statements
in one function.
-- Be seeing you.