Re: Connecting signal to destruction of an object - or - self-destructing handlers

[Murray Cumming <murrayc murrayc com>]

On Tue, 2017-07-04 at 09:44 +0100, Daniel Boles wrote:
> How/can I receive an event when some object of my choice is
> destroyed, so that I can take appropriate action?
>
> Here's an example I came up against lately. I should probably
> refactor the code so I don't need to do things this way... but it
> illustrates the question quite well. I have a ComboBox where, via
> some boring exposition, I want to put a signal_changed() handler on
> its StyleContext. However, that handler holds a reference to a row in
> the ComboBox's model. Therefore, I need to receive notification when
> that model dies (i.e. when all holders of RefPtrs release them), so
> that I can disconnect that signal_changed() handler and therefore
> stop it from trying to access a dead row.
[snip]

This shouldn't generally happen. The sigc::trackable base class should
take care of this. Maybe it would be best to try to reduce this to a
simple test case.

-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com