Article View: comp.std.c
Article #2790Re: Bitfields in unions
From: Eamonn McManus
Date: Mon, 22 Apr 1991 18:47
Date: Mon, 22 Apr 1991 18:47
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gvr@cs.brown.edu (George V. Reilly) writes:
>+ The ANSI C standard says explicitly that a union may contain a bitfield.
>Well, that's another thing that Harbison & Steele III have got wrong,
>then.
As I mentioned in my original message, K&R2 also seems to imply
obliquely that unions may not contain bitfields. Section A8.3:
...
A struct-declaration-list is a sequence of declarations for the
members of the structure or union:
...
Usually, a struct-declarator is just a declarator for a member of a
structure or union. A structure member may also consist of a
specified numbers of bits. Such a member is also called a
/bit-field/, or merely /field/; its length is set off from the
declarator for the field name by a colon.
struct-declarator:
declarator
declarator[opt] : constant-expression
Although the grammar allows union bitfields, the text by saying `A
*structure* member may also...' seems to be excluding unions. It should
say `A structure or union member...' or just `Such a member...'.
,
Eamonn
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!snorkelwacker.mit.edu!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!tcdcs!dce.ie!em From: em@dce.ie (Eamonn McManus) Newsgroups: comp.std.c Subject: Re: Bitfields in unions Message-ID: <orange@dce.ie> Date: 22 Apr 91 18:47:15 GMT References: <carbide@dce.ie> <680@taumet.com> <72969@brunix.UUCP> Organization: Datacode Communications Ltd, Dublin, Ireland Lines: 31