Re: Callback-related libraries and terminology

From:

"kanze" <kanze@gabi-soft.fr>

Newsgroups:

comp.lang.c++.moderated

Date:

28 Aug 2006 08:45:53 -0400

Message-ID:

<1156757785.367883.268880@m79g2000cwm.googlegroups.com>

Scott Meyers wrote:

kanze wrote:

Or inversely, what does boost::signal offer in addition to what
boost::function offers? I'm not that familiar with
boost::signal, but a quick glance at the doc didn't reveal the
most important addition for this sort of use: the possibility of
associating a filter with the callback, so that it will only be
called in certain circumstances.

I'm no expert, but AFAIK, Boost.Signal has no such functionality. Unlike
Boost.Function (and tr1::function),

That's my impression as well. Of course, since they take
boost::function as parameters, it wouldn't be difficult to
insert filtering there.

however, it is possible to "connect" multiple functions
(actually callable entities) to a single signal, which is why
I have this notion that a Boost signal can be thought of as a
"container" of callbacks.

A non-copiable container with a function interface which
automatically iterates over the elements.

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