Question about size and memory layout of a Union.

[James Kuyper Jr.]

Nothing does.

"next to each other" doesn't mean anything.
Bits in the same byte are only distiguishable
by the values that they represent.

Yes, but those bits can represent values in at least two different
types: the 32 bit type, or unsigned char. It's both meaningful, and
important, to realize that the standard imposes no requirements
connecting the value represented by a given bit in those two different
types.

Exception: if unsigned char is a 32 bit type, and the 32 bit integer
type we're comparing it with is char, signed char, or unsigned char,
then there is a required connection, of course.