subtraction between unsigned ints

[Henry Spencer]

In article <KURO.89Sep5111940 at shochu.Sun.Com> kuro at shochu.Sun.Com (Teruhiko Kurosaka - Sun Intercon) writes:
>Does pANSI defines the datatype of the result of subtraction
>between unsigned integers?  Would it be also unsigned?  Then
>what would be the result of subtraction of a number from a
>smaller number? ...

Unsigned - unsigned gives unsigned.  Unsigned arithmetic is done modulo the
type size, roughly speaking, so carries and borrows off the top end are
ignored.  The value of "(unsigned)3 - (unsigned)5" depends on how big the
unsigned type is, but on a 16-bit machine it's probably (unsigned)65534.
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