> Can you just take half the module, ctrl-x, ctrl-v into a new file, and get faster compilation times without having to do any massive refactors?…In Rust, almost always no, because of circular dependencies

This feels like a strange, overly-specific complaint. It reads a bit like “When I write entangled code, it’s hard to untangle”. Like, yeah, the only thing that’ll save you from that is…not writing entangled code? I’m not of the opinion that the argument of “yeah but C lets me do whacky stuff” is a particularly strong line.

FWIW, letting a module grow, and then splitting modules up by cut-and-pasting stuff out along natural domain lines generally _is_ how I write Rust. Largely due to how easy it makes it to construct modules and submodules.