Boost logo

Boost :

From: David Abrahams (dave_at_[hidden])
Date: 2003-02-08 17:05:58

"Peter Dimov" <pdimov_at_[hidden]> writes:

>>> except that the async_call doesn't need to know about Executors.
>> ...and that you don't need a special syntax to get the result out that
>> isn't compatible with functional programming. If you want to pass a
>> function object off from the above, you need something like:
>> bind(&async_call<int>::result, async_call<int>(bind(g, 1, 2)))
> Hmm. Actually I'll need a similar three-liner:
> async_call<int> f( bind(g, 1, 2) );
> // execute f using whatever Executor is appropriate
> // pass bind(&async_call<int>::result, &f) to whoever is interested

A little bit worse, you gotta admit.

> Synchronous RPC calls notwithstanding, the point of the async_call is that
> the creation+execution (lines 1-2) are performed well in advance so that the
> background thread has time to run. It doesn't make sense to construct and
> execute an async_call if the very next thing is calling result(). So in a
> typical scenario there will be other code between lines 2 and 3.

I agree, but I'm not sure what difference it makes.

> The bind() can be syntax-sugared, of course. :-)

I think some useful syntax-sugaring is what I'm trying to push for ;-)

>>>> int r = async_call<int>(create_thread(), bind(g, 1, 2));
>>>> int r = async(boost::thread(), g, 1, 2);
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>> int r = async_call<int>(rpc(some_machine), bind(g,1,2));
>>>> int r = async_call<int>(my_message_queue, bind(g,1,2));
>>> All of these are possible with helper functions (and the <int> could
>>> be made optional.)
>> Yup, note the line in the middle.
> The line in the middle won't work, actually, but that's another story.
> boost::thread() creates a "handle" to the current thread. ;-) Score another
> one for defining concepts before using them.

Oh, I'm not up on the new interface. How are we going to create a new

Dave Abrahams
Boost Consulting

Boost list run by bdawes at, gregod at, cpdaniel at, john at