Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!ames!pacbell!att!chinet!les
From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.lang.c
Subject: Re: struct accessing
Message-ID: <8869@chinet.chi.il.us>
Date: 5 Jul 89 20:40:51 GMT
References: <1545@stl.stc.co.uk> <470002@gore.com> <1411@garcon.cso.uiuc.edu> <18255@usc.edu>
Reply-To: les@chinet.chi.il.us (Leslie Mikesell)
Organization: Chinet - Public Access Unix
Lines: 16

In article <18255@usc.edu> blarson@basil.usc.edu (bob larson) writes:

>>There is a special dispensation, though: "If a pointer to a structure
>>is cast to the type of a pointer to its first member, the result
>>refers to the first member".  [8.3]

>There is at least one current (non-ansi) compiler that does not do this
>currently...

Is it possible to use the bsearch(), tsearch(), etc., library routines
for data in structs if a pointer to the struct cannot be cast to a
character pointer?  Alternatively, given a pointer to an element of
a struct, is it possible to deduce the base address (I assume this would
require pointer subtraction and thus be illegal)?

Les Mikesell