Bitarrays in the age of 64bit

[Jonathan M Davis]

On Friday, April 3, 2020 1:31:52 AM MDT Dominikus Dittes Scherkl via 
Digitalmars-d wrote:
> 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.

It has of course been a while since I saw this talk, since I haven't watched
it since it was live (so I may be remembering wrong), but it sounds like
this talk from dconf 2016 might be applicable:

http://dconf.org/2016/talks/sechet.html

- Jonathan M Davis