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From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.std.c
Subject: Re: Casting Function Pointers
Message-ID: <16248@smoke.brl.mil>
Date: 23 May 91 20:13:10 GMT
References: <1145@mwtech.UUCP>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 16

In article <1145@mwtech.UUCP> martin@mwtech.UUCP (Martin Weitzel) writes:
>	"The elaborate cast of the function argument casts the
>	arguments of the comparison function. These will generally
>	have no effect on actual representation but assure the
>	compiler that all is well."

K&R2 was written before the final ANSI C standard was published.
In fact, at the time it was written it was technically wrong on
this point.  However, since then X3J11 decided to require void*
and char* to have the same representation, and via a "trickle-up"
effect this implies compatiblility of the two types of function-
pointer argument to qsort().

However, I recommend coding the function according to the correct
interface specification and using casts within the function to
adapt it to the actual situation.