> I mean, with C++, the answer is something to the effect of "template expansion happens syntactically and generally has to be expressed in headers, leading to many megabytes of code that has to be compiled repeatedly with every translation unit". And that isn't really amenable to microoptimization. We all agree that it sucks, and probably can't be fixed with the language as it's specified, and chalk it up to a design flaw.

Isn't this what happens with rust too ? It's called "monomorphisation" there but everytime you use a Vec<i32> in Rust I would guess that what happens is fairly similar to a template instantiation.