Why must bitfields sum to a multiple of a byte?

[Era Scarecrow]

On Tuesday, 31 July 2012 at 17:17:43 UTC, Timon Gehr wrote:

> (Also IMO, the once-in-a-year wtf that is caused by 
> accidentally assigning in an if condition does not justify 
> special casing assignment expressions inside if conditions. 
> Also, what is an useless compare?)

  I've noticed in my experience, DMD gives you an error if you do 
a statement that has no effect; IE:

  1 + 2; //statement has no effect
  a == b;//ditto