+/**
+ * Mask out all bits, which are only there, because the number
+ * of bits in the set didn't match a unit size boundary.
+ * @param bs The bitset.
+ * @return The masked bitset.
+ */
+static INLINE bitset_t *_bitset_mask_highest(bitset_t *bs)
+{
+ bs->data[bs->units - 1] &= (bs->size & BS_UNIT_MASK) - 1;
+ return bs;
+}
+