Empty VS null array?

[ProgrammingGhost]

How do I find out if null was passed in? As you can guess I 
wasn't happy with the current behavior.

Code:

	import std.stdio;

	void main() {

		fn([1,2]);
		fn(null);
		fn([]);
	}
	void fn(int[] v) {
		writeln("-");
		if(v==null)
			writeln("Use default");
		foreach(e; v)
			writeln(e);
	}

Output

	-
	1
	2
	-
	Use default
	-
	Use default