typeclassProfile.scala

trait ArraySummer[-T] {
  def sum(t: T): Float
}

/** one TypeClass per concrete implementation */
object SpecificSummers {
  implicit object SimpleWrappedFloatArraySummer extends ArraySummer[SimpleWrappedFloatArray] {
    def sum(arr: SimpleWrappedFloatArray): Float = {
      ...
    }
  }

  implicit object FloatArrayAsBufferSummer extends ArraySummer[FloatArrayAsBuffer] {
    def sum(arr: FloatArrayAsBuffer): Float = {
      ...
    }
  }

  implicit object FloatArraySliceSummer extends ArraySummer[FloatArraySlice] {
    def sum(arr: FloatArraySlice): Float = {
      ...
    }
  }
}

/** one TypeClass for all implementations of ArrayLike[Float] */
object GenericSummers {
  implicit object ArrayLikeSummer extends ArraySummer[ArrayLike[Float]] {
    def sum(arr: ArrayLike[Float]): Float = {
      ...
    }
  }
}

Gist for a blog post: http://imranrashid.com/posts/profiling-bytebuffers/
Full code is at https://github.com/squito/oleander/blob/blog_post_profiling_interfaces/src/test/scala/com/imranrashid/oleander/ByteBufferBackedTest.scala