Re: [boost] Re: A new boost::thread implementation?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2003-02-10 08:13:36

David Abrahams wrote:
> "William E. Kempf" <wekempf_at_[hidden]> writes:
>
>> David Abrahams said:
>>> No, my fault.  Syntactically, I should've written this:
>>>
>>>     async_call<int> f(create_thread(), bind(g,1,2));
>>>     int r = f();
>>
>> Do you want it to be "int r = f();" or just "int r = f;" or even
>> "int r = f.result();" or similar?
>
> My other message makes it clear (I hope) that I want what I wrote
> above.

Are you sure that you really want the above? Or are you speculating that you
might want something like the above in a hypothetical situation that you
haven't encountered yet but you might in the future?

>> The f() syntax makes it look like you're invoking the call at that
>> point, when in reality the call was invoked in the construction of
>> f.
>
> You're just invoking a function to get the result.  f itself is not
> the result, so I don't want to use implicit conversion, and f.result()
> does not let f behave polymorphically in a functional programming
> context.

f does not behave polymorphically, or rather, its polymorphic behavior isn't
useful. In the generic contexts I'm familiar with, generators are only used
to produce a sequence of values.

I am not saying that this is never useful, but syntax should target the
typical scenario, not corner cases.

It makes a lot more sense (to me) to reserve operator() for the Runnable
concept, since that's what Boost.Threads currently uses.