[LCP]struct & union

[Paul Gearon]

On Mon, 4 Feb 2002, shahnavaz wrote:

> hi,
> 	I think that has solved my doubt.But can you tell me why is int and float
> have same size then(ofcourse on linux i386).

The size of a float is part of the standard.  If you check out the
"reading" section of the gcc site it says that gcc is s based on C99.
The C99 standard says that it extends C89, and the C89 Rational document
says:

"Single precision (32-bit) floating point is considered adequate to
support a conforming C implementation."

http://www.lysator.liu.se/c/rat/b.html#2-2-4-2-2

Note that it doesn't *have* to be 4 bytes, but it is anyway.

(now for the part I don't really know)
ints are similar.  From memory, ints used to conform to the default word
size of the machine - though I may be wrong here.  People started to
standardize on the size of the int by the time 32bit architectures come
in.  For example, when M$ went from win16 to win32 they changed ints from
16 bit to 32 bit.  However, now that win64 is available I think M$ left
the size of an int at 32 bits so as not to break too many existing
applications.

Someone here may have a more accurate picture of what size an int is in a
given circumstance.  These days I just accept that it's 32 bits since
everyone seems to have standardized on that size.



Regards,
Paul Gearon

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