To be honest, I'd struggle to think of a language with generics or dynamic typing where you couldn't do function composition.

Even in C, you could do something like in this godbolt link (ugly, I know):

https://godbolt.org/z/aKTz6fdbc

That's not quite the same (functionally) as the Rust solution though? Unless you meant to just illustrate a minimal PoC, in that case I suppose it does the job. More importantly (IMO) Rust allows us to be truly generic without sacrificing any type safety in the process.