Re: [boost] Trolls and Signals

From: Terje Slettebø (tslettebo_at_[hidden])
Date: 2002-05-24 21:16:13

>From: "Beman Dawes" <bdawes_at_[hidden]>

> At 09:00 AM 5/23/2002, Douglas Gregor wrote:
>
>  >We can't just replace the 'signals' namespace with a (user-defined, but
>  >defaulted) macro BOOST_SIGNALS_NAMESPACE because that doesn't play
nicely
>
>  >with (shared) libraries.
>  >
>  >Here's a possibility: the Signals library moves from the boost::signals
>  >namespace to the boost::signalslib namespace (better names anyone?
> please?).
>  >
>  >Then the Signals library also has this:
>  >
>  >#ifndef signals
>  >namespace boost {
>  >  namespace signalslib {}
>  >  namespace signals = signalslib;
>  >}
>  >#endif
>  >
>  >So when Qt is not available, the boost::signals namespace alias is used
> and
>  >nobody knows the difference (would someone confirm this? I haven't
needed
>
>  >namespace aliases before...)...
>
> Ugly. Think about it long and hard. As Boost gets used with more and more
> third party libraries, we are going to run into this sort of problem more
> often.

This is one of the problems with using a proprietary preprocessor like Qt
does (the MOC), which implements these new keywords, making these clashes. I
think it would have been better if they had implemented the signal/slot, and
reflection capability, in the language itself.

> Do we really want to change our libraries because of the rudeness of
> others?

I don't think so, either. The problem is at their end, so to speak. :) They
introduce extensions, making it incompatible with standards compliant code.
I think this is something they should resolve, not other libraries.

However, as with noncompliant compilers, this also comes down to what is
practically possible. Maybe a configuration switch could be used for this,
in config.hpp.

Regards,

Terje