function overload on full signature?

[bearophile]

monarch_dodra:

> I mean, are there even any real use-cases for overload on 
> return type?

In Haskell many functions are "overloaded" on the return type 
(like the fromString function), and it's nice. But Haskell is 
able to do it because it has a global type inferencer.

Bye,
bearophile