Re: [boost] Re: Re: [signals] Performance

From: Doug Gregor (dgregor_at_[hidden])
Date: 2004-12-02 18:02:14

On Dec 2, 2004, at 3:03 PM, Fredrik Blomqvist wrote:

> Perhaps this could be of some interest in this discussion.
> http://www.codeproject.com/cpp/FastDelegate.asp
> The article talks about low-level optimization of delegates on a wide 
> range
> of platforms.

We have to be a little careful here, because the author is using some 
(really neat!) non-portable tricks.

> To quote: "Initially, I used boost::function, but I found that the 
> memory
> allocation for the delegates was consuming over a third of the entire
> program running time!"
>
> Regards
> // Fredrik Blomqvist

Yes, this is a good point... one common case we had previously talked 
about optimizing is everything related to:

        function<int(int)> f(boost::bind(&X::m, x_ptr, _1));

Since most slots just bind an object to the member pointer, being able 
to store these in a function<> instance without allocating memory could 
be a big win. I know several people have asked for it on more than one 
occasion: the problem is implementing it portably (in a practical 
sense; making it standard C++ is easy).

        Doug