> Things like dynamically updated graphs are nearly impossible to write in Rust Just curious, have you tried to handroll these, or have you used libraries? (eg. petgraph, though I don't know if it'd suit your usecases.)

I'm a Rust connoisseur, but I'd agree with 'nearly impossible to write', which is why I'd (first of all) try to grab a library, assuming I'm doing anything complicated with graphs. If it's very simple and specific, I'd try to go through the list of possible graph representations (eg. adjacency lists), and pick a suitable one, but never store nodes directly, rather store indices (while the nodes are stored in some sort of vector).