What really bugs me is that the behaviour of each(SCALAR) and friends is dependent on the internal storage format of the value passed to it.

An object that overloads %{} is not considered a hash for each(SCALAR), so each(SCALAR) isn't safe to use unless you create the hash yourself.

After years of work, they finally removed just about every trace of the "Unicode Bug" from the core only to add another bug of the same class. And they knew they were doing this!