Bit type?

[Dan]

I thought I recalled D having a "bit[]" type with the restriction that you could only use bit[n*8]?

I'm asking because I've been developing an interest in DNA.  I had thought it would be an amazing project to produce an open source DNA format.  Raw DNA uses two bits, but you could probably need another 2 per base pair for expression.  From there, you have raw DNA.  You want to build slices, as slices get copied off to make siRNA and mRNA and such.  So mapping out which parts of the DNA are used to make copies of what tends to be useful.

D just seems to fit together quite well - but I want an easy 4-bit type to work with.

Who likes the idea?