Depending on how you plan to use it, a bitset may be more efficient (at least memory wise). E.g. https://gist.github.com/cslarsen/1590498 https://gist.github.co

Depending on how you plan to use it, a bitset may be more efficient (at least memory wise). E.g. https://gist.github.com/cslarsen/1590498 https://gist.github.com/cslarsen/1590498