Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!shadooby!accuvax.nwu.edu!nucsrl!gore!jacob
From: jacob@gore.com (Jacob Gore)
Newsgroups: comp.lang.c
Subject: Re: struct accessing
Message-ID: <470001@gore.com>
Date: 25 Jun 89 16:43:28 GMT
References: <1545@stl.stc.co.uk>
Reply-To: jacob@gore.com (Jacob Gore)
Organization: Gore Enterprises
Lines: 40

/ comp.lang.c / dsr@stl.stc.co.uk (David Riches) / Jun 22, 1989 /
struct fred
  {
   int tom;
   int dick;
   int harry;
  }
... in my dreams, I would like to have a statement which says :-

	person = fred.$field_name$

where $field_name$ means "take my contents and use that as the field
name.".
----------

Something that comes close:

struct fred
  {
   int tom;
   int dick;
   int harry;
  } fred_proto;
#define TOM	(&fred_proto.tom   - &fred_proto)
#define DICK	(&fred_proto.dick  - &fred_proto)
#define HARRY	(&fred_proto.harry - &fred_proto)
...
int field_name;
struct fred fred;
int *person;
...
person = &fred + field_name;


Or some variation of the above, like
#define FIELD(aStruct,offset)	(*(&aStruct + offset))
int person = FIELD(fred,TOM);

--
Jacob Gore	Jacob@Gore.Com		{oddjob,chinet,att}!nucsrl!gore!jacob