+{-The firstPowerOf2 function works by setting all bits on the right-hand
+side of the most significant flagged bit to 1, and then incrementing
+the entire value at the end so it "rolls over" to the nearest power of
+two.
+-}
+
+-- | Computes the next-highest power of two for a particular integer,
+-- @n@. If @n@ is already a power of two, returns @n@. If @n@ is
+-- zero, returns zero, even though zero is not a power of two.