Allows the specification of bit-based structures and provides an intuitive way of access data. Example: class Flags < StructBase unsigned :direction, 4 unsigned :multiplier, 2 unsigned :offset, 2 end class Entry < StructBase unsigned :offset, 4 nested :flags, Flags unsigned :address, 24 unsigned :cache_id, 16 end In contrast to the already available http://raa.ruby-lang.org/project/bit-struct/ implementation, BitStructEx allows nested structures which are not aligned on byte boundaries.