title: Could not find implicit value for parameter ordering
body: <p>I get the following error when trying to compile this:</p>
  
  <p>Btree.scala:9: error: could not find implicit value for parameter ordering: Ordering[K]
          abstract class Node[K,V] extends TreeMap[K,V]</p>
  
  <p>TreeMap is supposed to accept an implicit Ordering[A] val which I provide. Perhaps the implicit parameter needs to be in object Tester where the Btree(TreeMap) is instantiated?
  I would prefer to keep the implicit declaration inside of the Btree class because I would like Ordering to have a type K that implements Comparable[K].  Make sense? </p>
  
  <pre><code>package disttree {
      import scala.collection.immutable.TreeMap
  
      class Btree[K &lt;: Comparable[K],V](fanout:Int) {
          implicit object DefaultOrder extends Ordering[K] {
              def compare(k1: K, k2: K) = k1 compareTo k2
          }
  
          abstract class Node[K,V] extends TreeMap[K,V]
  
          class InnerNode[K,V] extends Node[K,V]
  
          class LeafNode[K,V] extends Node[K,V]
  
          val root = new InnerNode[K,V]()
  
          def search(n: Node[K,V], key: K): Option[(K,V)] = {
              return n.find(_ == key)
          }
  
          def insert(key: K, value: V) { }
  
          def delete(key: K) { }
      }
  }
  
  import disttree._;
  object Tester {
      def main(args: List[String]) = {
          var t = new Btree[Int, Any](2)
          t.insert(1, "goodbye")
          Console.println(t)
      }
  }
  </code></pre>