Re: [Boost-users] [Signals] Proposal effort for TR2

From: Douglas Gregor (doug.gregor_at_[hidden])
Date: 2005-07-27 21:47:45

On Jul 27, 2005, at 2:45 PM, Edward Diener wrote:

> Doug Gregor wrote:
>> At the C++ committee meeting in Lillehammer last April, I'd asked if
>> there was any interest in a TR2 proposal for the Signals library, and
>> got a positive response. I'll be collaborating with the libsigc++ 
>> folks
>> to put together a proposal for the upcoming meeting, which will be
>> discussed on the libsigc mailing list:
>>
>> 	http://mail.gnome.org/mailman/listinfo/libsigc-list
>
> Are the TR2 discussions about signals going to be over in the 
> libsigc++ forum ?

Yes.

> That might imbalance the proposal in my mind toward lisigc++ rather 
> than Boost
> Signals, and I hope that does not happen.

Have you seen the libsigc++2 interface? libsigc++ 1.x was very 
different, and it's (IMHO!) poor syntax was the impetus for 
Boost.Signals. However, with libsigc++2, the two libraries' interfaces 
have practically converged already, and it's just a matter of hammering 
out little details.

>>
>> We'll naturally be taking the good features from both libraries
>> (tracking, combining, syntax, etc.) and tossing out the bad (*ahem*
>> named slot groups)
>
> I do not think that slot groups are bad. They provide an easy ordering 
> mechanism
> for signals. I would hate to see flexibility thrown out just because 
> the
> performance has not been optimized depending on whether or not any 
> slot groups
> are used for any given signal.

They require a great deal of implementation and specification 
complexity, which results in an inefficient (in memory and speed) data 
structure. Unless we can come up with a more intelligent data structure 
for them, I think we should keep them out of the proposal. But the 
libsigc++ mailing list is the better place for this :)

        Doug