ContextBoundsSyntax.scala

class ContextBoundsSyntax {

  trait Monoid[A] {
    def zero:A
    def append (a:A, b:A) : A
  }

  implicit object AdditiveInt extends Monoid[Int] {
    def zero = 0
    def append (a:Int, b:Int) = a + b
  }

  def gimmeZero[T : Monoid](x: T): T = {
    implicitly[Monoid[T]].zero
  }

  def gimmeZero2[T: Monoid](x: T): T = {
    implicitly[Monoid[T]].zero
  }

  def foo() {
    gimmeZero(100)
  }
  
}
  

gimmeZero and gimmeZero2 are the same disassembled with javap -c

  public <T> T gimmeZero(T, ContextBoundsSyntax$Monoid<T>);
    Code:
       0: getstatic     #41                 // Field scala/Predef$.MODULE$:Lscala/Predef$;
       3: aload_2
       4: invokevirtual #45                 // Method scala/Predef$.implicitly:(Ljava/lang/Object;)Ljava/lang/Object;
       7: checkcast     #47                 // class ContextBoundsSyntax$Monoid
      10: invokeinterface #51,  1           // InterfaceMethod ContextBoundsSyntax$Monoid.zero:()Ljava/lang/Object;
      15: areturn

  public <T> T gimmeZero2(T, ContextBoundsSyntax$Monoid<T>);
    Code:
       0: getstatic     #41                 // Field scala/Predef$.MODULE$:Lscala/Predef$;
       3: aload_2
       4: invokevirtual #45                 // Method scala/Predef$.implicitly:(Ljava/lang/Object;)Ljava/lang/Object;
       7: checkcast     #47                 // class ContextBoundsSyntax$Monoid
      10: invokeinterface #51,  1           // InterfaceMethod ContextBoundsSyntax$Monoid.zero:()Ljava/lang/Object;
      15: areturn