Macro bitbox 

macro_rules! bitbox {
    ($($arg:tt)*) => { ... };
}

Boxed Bit-Slice Constructor

This macro creates encoded BitSlice buffers at compile-time, and at run-time copies them directly into a new heap allocation.

It forwards all of its arguments to bitvec!, and calls BitVec::into_boxed_bitslice on the produced BitVec.