Re: [Boost-users] future<>.then and promises

Subject: Re: [Boost-users] future<>.then and promises
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-06-30 06:21:43

Le 28/06/13 20:39, Klaim - Joël Lamotte a écrit :
>
> On Fri, Jun 28, 2013 at 7:48 PM, Vicente J. Botet Escriba 
> <vicente.botet_at_[hidden] <mailto:vicente.botet_at_[hidden]>> wrote:
>
>     When I fix it, the continuation would not be called immediately
>     but as the doc states it should
>
>     "- If the parent was created with |promise<<| or with a
>     |packaged_task<>| (has no associated launch policy), the
>     continuation behaves the same as the third overload with a policy
>     argument of |launch::async | launch::deferred| and the same
>     argument for func.
>     "
>
>
>
> Ah yes, ok, so it will be called at least when future.get() will be 
> called, if I understood correctly?
Yes.
>
>>     1.
>>
>>        ft.then( []( future<T> f ) { return 42; } );
>>
>>     This will not compile (VS2012U3) because there is an attempt to
>>     copy future<T> (which looks like a bug I reported where returning
>>     a future would
>>     trigger copy instead of moving the future, bug fixed since then
>>     so I'm a bit surprise about this one)
>>
>     Currently the prototype of a continuation takes a future by
>     reference, but I could change it to by value (which need to move
>     the future.
>
>
>
> I thought the original standard proposition was moving the future into 
> the callback, or is this point under discussion?
>
>
You are right. I will fix this soon.

best,
Vicente