Clarification: Go allows for a very simple multi-file. It’s one feature I really like, because it allows splitting otherwise coherent module into logical parts.
For example, you can't split up a module into foo.rs containing `Foo` and bar.rs containing `Bar`, both in module 'mymod' in such a way that you can `use mymod::Bar and foo.rs is never built/linked.
My point is the granularity of the package/mod encourages course-grained deps, which I argue is a problem.
yesn't, you can use feature flags similar to `#if` in C
but it's also not really a needed feature as dead code elimination will prune out all code functions, types, etc. you don't use. Non of it will end up in the produced binary.
Historically Rust wanted that foo.rs to be renamed foo/mod.rs but that's no longer idiomatic although of course it still works if you do that.
in rust crates are semantically one compilation unit (where in C oversimplified it's a .h/.c pair, and practically rustc will try to split it in some more units to speed up build time).
the reason I'm pointing this out is because many sources of "splitting a module across files" come from situations where 1 file is one compilation unit so you needed to have a way to split it (for organization) without splitting it (for compilation) in some sitation