[Impossible]

Future of coding is a cool programming community that discusses graphics C and C++ occasionally. A lot of the focus is on visual programming, end user programming, esoteric languages and no code/low code. Lobster.rs as suggested is pretty good for general technical discussion but graphics on a non-surface level rarely comes up.

For graphics and C++ Twitter is probably the best option, follow some important graphics folks (say Peter Shirley, Angelo Pesce or John Carmack) and you'll get some interesting threads. There are also some good graphics programming Reddits. A lot of the best discussion happens in invite only places for me now, having some contacts in the industry helps there.