Re: [boost] Review Request: future library (N2561/Williams version)

From: Anthony Williams (anthony_w.geo_at_[hidden])
Date: 2008-05-08 08:35:30

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

> ----- Original Message ----- 
> From: "Anthony Williams" <anthony_w.geo_at_[hidden]>
> To: <boost_at_[hidden]>
> Sent: Tuesday, May 06, 2008 8:42 AM
> Subject: Re: [boost] Review Request: future library (N2561/Williams version)
>
>
>> "vicente.botet" <vicente.botet_at_[hidden]> writes:
>>
>>> why we don't need to protect get_future() function of multiple thread
>>> access?
>>
>> By design you can only call this function once, so if multiple threads 
>> called
>> it concurrently and that was safe, only one would get the future, and the
>> other would get an exception. The user should therefore use appropriate
>> synchronization to ensure correct results anyway, so making this call
>> thread-safe would not be of benefit.
>>
>
> I don't understand the need of this function. Could you show a use case for 
> promise::get_future() function?

promise::get_future() is the only way to get a future from a promise. Since
the whole point of using promise is to get the future, it's rather pointless
without it.

Were you getting at something else?

Anthony
-- 
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