Additional Glib::RefPtr Safety Mechanism

[Karsten Pedersen <kpedersen gmx com>]

Hi all,

One area of C++ that always frustrates me is safety. Smart pointers
such as the Glib::RefPtr go a good way to avoid dangling pointers, use
after free, etc. However one area where this (and std::shared_ptr) is
lacking is that it is very easy for "this" to dangle and there really
is no protection against it. Check out a very simple example here:

https://github.com/osen/sr1/blob/master/src/tests/dangling_this.cpp

Would it interest the gtkmm project to safeguard against this? I have
prototype code (in the same repository linked above) that augments a
basic shared_ptr implementation with an "operator->" that locks the
smart pointer until it has returned.
If error such as the one above occurs it immediately aborts and
notifies the developer that things are wrong.

I have devised systems to perform the same "locking" mechanism that can
be used with *ptr, std::vector::at and iterators. Again in that same
repository you can see a number of test cases that are protected
against.

In particular I can see this being really nice to enable in "debug"
builds. Then upon a release build there is absolutely no additional
overhead (because all this extra instrumentation has been stripped
out).

What do you guys rekon? Is this idea of interest?

Best regards,

Karsten