🚀 go-pugleaf

fred@genesis.demon.co.uk writes:
 >In article <4k1q3p$5bj@solutions.solon.com> news@Thinkage.On.CA  writes:
 >>to a double *. Since malloc guarantees alignment (actually, only *after*
 >>casting, but only a very malicious malloc would do that to you), this can
 >>safely be done.
 >
 >The standard actually says 7.10.3:
 >
 >"The pointer returned if the allocation succeeds is suitably aligned so that
 > it may be assigned to a pointer to any type of object..."
 >
 >So the alignment is guaranteed for the pointer returned i.e. prior to
 >conversion.

No, it only says that you can do the assignment, i.e., it won't cause a trap
or somesuch. The assignment itself might change the pointer value. After the
assignment eveything must be as we all expect. Imagine a malloc that returns
a pointer to a non-aligned byte, and the casting works by rounding forward
to the next alignment boundary.
-- 
David Tanguay       dat@Thinkage.on.ca       http://www.thinkage.on.ca/~dat/
Thinkage, Ltd.           Kitchener, Ontario, Canada          [43.24N 80.29W]