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

From: Douglas Gregor (gregod_at_[hidden])
Date: 2003-08-26 20:02:51

On Tuesday 26 August 2003 07:36 pm, shyamemani wrote:
> I hate writing code in mailing list but here is a sample of what I
> want to do.  I have a tree data strucutre class which fires event and
> each event has some different parameters that are passed to it.  What
> I want to illustrate is that by calling one register function I get
> access to three events.  In boost.signal this would require that the
> client call the connect for each event.  Is this a good application
> for this library?

Perhaps not. When you have multiple events going to a single listener from a 
single source, signal/slot mechanisms aren't as useful as the 
interface/listener paradigm you are already using. Signals might be 
appropriate if you had a single event that could be any of those three:

        enum NodeEvent { node_added, node_changed, node_deleted };
        boost::signal<void (NodeEvent event, Node* node)> onNodeEvent;

This may have some advantages over the iterface/listener approach you're using 
(for instance, the automatic disconnect when trackable objects are destructed 
or the ability to use Bind/Lambda), but it's very likely that Signals is not 
the right choice for this interface.

        Doug