Re: [boost] [Boost-announce] Futures - Reviews Needed (January 5, 2009)

Subject: Re: [boost] [Boost-announce] Futures - Reviews Needed (January 5, 2009)
From: Steve Karmesin (steve.karmesin_at_[hidden])
Date: 2009-01-03 12:43:33

A couple of points that I would want to see clarified on the Boost.Futures
proposal to make sure the major design decisions are vetted:

The first is on callbacks.  The description does not make clear what thread
the callback is required to be done in.  I would guess that the easiest
implementation is to put it be in the thread in which the promise is
fulfilled, but I would want that to be specified in the interface since it
would affect how I would use it.

A second question on callbacks: Would it not make sense to use the boost
signals package for this?  I think that provides a very rich interface for
binding values to the callbacks, and that is very useful.

Next, I'm wondering about the reference semantics.  Is that there because it
is not sensible to copy them?  If that is the case then the alternative
would be to prohibit copy and not require memory management under the hood.
The downside there is that the user would usually have to use pointer to
futures/promises in order to build containers of them.  On the whole I think
I come down on the side of liking the reference semantics, but I don't think
it is a no brainer and would want to see some commentary on it.

In general I like this package a lot and wish I could use it on my current
project :-).

-Steve Karmesin