That's fair, and I'm not a compiler engineer so I'll avoid making authoritative claims :-). But a C/C++ compiler is a whole thing, with some pretty intense perf

That's fair, and I'm not a compiler engineer so I'll avoid making authoritative claims :-). But a C/C++ compiler is a whole thing, with some pretty intense performance requirements, wouldn't you say? Mainly I was speaking from the experience of trying to write more complicated parser & tree transformation pieces in Rust and finding the ownership stuff a hassle.