variable '_' is unbound

[Vance Shipley]

What is wrong with this:

	foo(Arg) when bar == Arg; <<_:16>> == Arg -> ok.


When I try to compile it I get:

	1> c(t).
	./t.erl:4: variable '_' is unbound
	error

This is using R8B-1.

	-Vance