Re: [Boost-Users] Re: boost::function syntax

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-08-26 15:32:07

On Tuesday 26 August 2003 02:56 pm, shyamemani wrote:
> When I mentioned the performance cost I was comparing two programming
> techniques.  a) Using call back interfaces and b) using
> boost::functions.  As Douglas mentioned that if the operator is
> inlined, the performance of boost::function will be better since
> virtual functions cannot be inlined by the compiler and I agree with
> him.

I think we have a little communication confusion, and I think it's my fault. 
What do you mean by "call back interfaces"? Function pointers? Hardcoded 
calls to particular routines? Or are by "interfaces" are you talking about 
something akin to Java's interfaces?

Calling through a boost::function will incur essentially the same overhead as 
calling through a virtual function. 

>         But with interfaces I can define multiple functions in it and
> register to recieve multiple events.  Use of this in boost::function
> would require calling register multiple times.  I think I am
> considering wrong application of the library.

boost::function doesn't support multiple events. That's why we have 
Boost.Signals built on top of boost::function.

        Doug