Context Bound

A context bound describes an implicit value. It is used to declare that for some type A, there is an implicit value of type B[A] available. The syntax goes like this:

def f[A : B](a: A) = g(a) // where g requires an implicit value of type B[A]

How can B[A] implicit parameter be reached?

def f[A : B](a: A) = {
  val ev = implicitly[B[A]]
  g(a)
}

De-sugared version of Context Bound:

def g[A](a: A)(implicit ev: B[A]) = g(a)