Justification for Rust not Supporting Function Overloading (directly)

[leodasvacas]

tldr: Generics and function overloading don't play along well. Quoting boats here:

@withoutboats

The feature your asking for is just plain old function overloading, which Rust does not have. There are a few reasons I think its unlikely Rust will have this feature any time soon:

1. It’s not usually that useful, since you can just use a different method name.

2. Using it is often not a great idea, because if these methods have different signatures and different implementations, like as not they should have a different name.

3. In a language with a lot of type parameters flying around like Rust has, proving that the two signatures are actually disjoint is not trivial. We’d have to have a whole coherence system for function signatures, and before long we’d be talking about specialization between signatures.