Re: [Boost-users] logical_and, boost::bind, and boost::function

From: Douglas Gregor (doug.gregor_at_[hidden])
Date: 2005-08-10 15:12:51

On Aug 10, 2005, at 1:47 PM, Simmons, Aaron wrote:

>> Alan's post made me realize what's happening. Indeed, this last bind()
>> doesn't know that funcFoo and funcBar are functions that it should
>> call. You can tell it to consider them as functions by calling bind()
>> on them:
>
> Rather than wrapping another bind around them, is it possible to do 
> some
> kind of clever casting, so that bind wouldn't see them as booleans?

Not that I can think of.

> Btw, is the way I'm using function and bind not an intended use case?
> It seems natural enough, but by its behavior perhaps no one thought
> about it before...

We typically advise users to keep their bind() expressions together and 
put the result into a function<> at the end, to minimize the 
performance degradation associated with function<>. In that sense, it's 
somewhat unexpected.

I'd like to hear Peter Dimov's take on this one. My gut reaction is 
that what you wrote should probably work, e.g., function<> objects 
should be recognized as nested bind expressions.

        Doug