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

You can reduce Miles' solution to only use 1 extra line by doing this:

Add an implicit conversion from A : Numeric to Numeric[A]#Ops

object Ops {
  implicit def numeric[A : Numeric](a: A) = implicitly[Numeric[A]].mkNumericOps(a)
}

Then bring this into scope in your method

def g[T : Numeric](a: T, b: T) = {
  import Ops.numeric
  a * b
}

See Scala ticket 3538 for more info.