Not all implicit
functions are conversions!
Any implicit function with a single argument could be used as a conversion, but that's not the only use-case for implicits.
Functions are just another type and, as such, you can specify an implicit argument as in (implicit fn: (Int, Int) => Int)
I wouldn't do this though, anything you intend to pass as an implicit should have a far more specific type that better self-documents its intended purpose.