gistfile1.txt

scala> :paste
// Entering paste mode (ctrl-D to finish)

class A[T] {
  def add(n: Int)( env: T =:= Int = null): Boolean = if(env == null) true else false
}

val a = new A[Int]
a.add(1) // 2


// Exiting paste mode, now interpreting.

<pastie>:18: error: missing argument list for method add in class A
Unapplied methods are only converted to functions when a function type is expected.
You can make this conversion explicit by writing `add _` or `add(_)(_)` instead of `add`.
       a.add(1) // 2