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From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: Pointers on pointers.
Message-ID: <15729@smoke.brl.mil>
Date: 6 Apr 91 00:12:48 GMT
References: <1991Apr5.173843.2435@bnlux1.bnl.gov>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 18

In article <1991Apr5.173843.2435@bnlux1.bnl.gov> reilly@bnlux1.bnl.gov (kevin reilly) writes:
>If dataType1 is known in advance as containing only ints can I do the
>following:
>declaration: void FUNC1(int *input);
>usage: FUNC1(&strType.data1);
>as opposed to the more correct procedure:
>declaration: void FUNC1(dataType *input);
>usage: FUNC1(&strType.data1);

If representation of pointer-to-int happens not to use the same scheme
as representation of pointer-to-structure, then using the incorrect
type would probably result in a malfunction.

You could also invoke the function with argument &strType.data1.x, where
"x" is the name of the first (int) member of the structure.

A more general comment is that there appears to be an imperfect
implementation of data abstraction underlying this example.