Re: [boost] Futures Review - minor implementation details

Subject: Re: [boost] Futures Review - minor implementation details
From: Anthony Williams (anthony.ajw_at_[hidden])
Date: 2009-01-20 06:40:44

"vicente.botet" <vicente.botet_at_[hidden]> writes:

> Hi Anthony,
>
> Some minor implementation details:
> Why there is not other.future reset in
>         shared_future(shared_future && other)
>         {
>             future.swap(other.future);
>         }
>         shared_future(unique_future<R> && other)
>         {
>             future.swap(other.future);
>         }
>
> How the move is made?

These are the constructors. The "future" member is initially NULL, so
the swap sets "other.future" to NULL whilst transferring the value
from "other.future" to "this->future"

> Is 
>             future.swap(other.future);
>             other.future.reset();
> more efficient than
>             future.reset(other.future);
>             other.future.reset();
> ? Otherwise you can change it in:

The former avoids incrementing any reference counts. The
latter has to increase the reference count on *other.future just to
decrease it again with the reset.

> And once shared_ptr implements movable you could use 
>     future = move(other.future);
> Isn't it?

Yes.

Anthony
-- 
Anthony Williams            | Just Software Solutions Ltd
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