Type punning in C

[Wade Guthrie]

>In article <11242 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn) writes:

	However, C does provide "union" types that can be used for such 
	purposes.  Load the bit pattern into the integer union member 
	and extract it via the floating-point member.

lhf at aries5.uucp (Luiz H de Figueiredo) writes:

	Provided both members have the same size!  Otherwise, try

	union
	{
	 float f;
	 unsigned char b[sizeof(float)];
	};

I thought that the standard said (as opposed to what I remember reading
in K&R I) that members of unions do NOT have to have zero offset?  In
this case, none of the above work (and, BTW, breaks a lot of existing
code).

Do I completely misunderstand what the standard said, or is the stuff
above just not portable to ANSI conformant compilers (God, I didn't mean
for that to sound as snotty as it did -- please take that as a neophyte
asking an innocent question).


Wade Guthrie
evil at arcturus.UUCP
Rockwell International
Anaheim, CA

(Rockwell doesn't necessarily believe / stand by what I'm saying; how could
they when *I* don't even know what I'm talking about???)