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sub_of(3)		   Library Functions Manual		     sub_of(3)

NAME
       sub_of -	subtract two integers, check for arithmetic overflow

SYNTAX
       #include	<libowfat/rangecheck.h>

       int sub_of(dest,a,b);

DESCRIPTION
       If calculating a-b is possible without causing undefined	behavior or an
       arithmetic  overflow in C, and the result fits into the destination in-
       teger type, do dest=a-b and return 0.

       Otherwise, return 1.

       Note: This is a macro, so dest does not have to be a pointer.

BUGS
       In the multiplication functions,	a return value of  1  signals  success
       and 0 failure. In add_of, sub_of	and assign it's	the other way around.

SEE ALSO
       add_of(3),  assign(3),  imult16(3), umult16(3), imult32(3), umult32(3),
       imult64(3), umult64(3)

								     sub_of(3)

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