Bitarrays in the age of 64bit

[Dominikus Dittes Scherkl]

It was said that implementing bitarrays is complicated, because 
of the indexing.

Has anybody ever considered to use bit-pointers?
Nobody really uses the full address range that 64bit pointers 
have - in fact some hardware internally still uses 48bit or 56bit 
address-registers, so instead adding three lower address bits 
would not cost a lot (just forward bit 3..58 to the register 
instead of bit 0..55).
This would also allow for implementing 2bit-types (one that I 
really would appreciate, because it can represent sign values, 
providing -1, 0, 1 and NaN - which is necessary as a comparison 
result for non-ordered values), and 4bit-types (so called 
nibbles).
And with bit-pointers of course implementing arrays of boolean, 
sign, nibbles or even odd-length types would be straight forward. 
All the strange side-effects of byte clustering would vanish.

Just an idea.