Where can gtkmm be discussed?

What subject material is appropriate to discuss?

The Discourse forum is used for discussion of development, suggestions, and improvements of the C++ wrappers themselves. There is also discussion of the use of the wrapper. Bugs are better reported and discussed in GitLab issues and merge requests.

Mailing List Archives

There is an old mailing list, which is now closed for new posts. It is archived at the gtkmm-list archive.

MARC archives messages even from before 2002, and has a more reliable search engine.

IRC channel

Development can also be discussed in the #c++ channel on irc://irc.gnome.org/#c++, but questions are more likely to be answered properly on Discourse. Plus, Discourse is archived, so others can benefit from the answers.