Why does Numeric behave differently than Ordered?

Question

Scala has a number of traits that you can use as type classes, for example Ordered and Numeric in the package scala.math.

I can, f

Answer 1

Ordered is just a few simple pimped methods that return either Int or Boolean, so no type-trickery is needed.

Numeric, on the other hand, has methods that return different types depending on the exact subclass used. So while Ordered is little more than a marker trait, Numeric is a fully-featured type class.

To get your operators back, you can use mkNumericOps (defined in Numeric) on the lhs operand.

UPDATE

Miles is quite right, mkNumericOps is implicit, so just importing that instance of Numeric will give you back all the magic...