To: linux-kernel@vger.kernel.org
From: Jan Blunck <jblunck@suse.de>
Subject: Re: [PATCH RFC] struct list_node
Date: Thu, 14 Jun 2007 10:03:51 +0000 (UTC)
Organization: SUSE LINUX Products GmbH, GF Markus Rex, HRB 16746 (AG
	Nuernberg)
Message-ID: <f4r3q7$fin$1@sea.gmane.org>
References: <1181452290.16428.7.camel@localhost.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
User-Agent: pan 0.119 (Karma Hunters)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1065
Lines: 29

On Sun, 10 Jun 2007 15:11:30 +1000, Rusty Russell wrote:

>  
> +/* A list node is the same as the head of the list, but it's useful to
> + * think of them as a separate type. */
> +struct list_node {
> +	struct list_head h;
> +};
> +
> +/* This allows us to support old style list_head as well as list_node. */
> +union list_head_or_node {
> +	struct list_head *_h;
> +	struct list_node *_n;
> +};
> +union list_head_or_node_const {
> +	struct list_head *_h;
> +	struct list_node *_n;
> +	const struct list_head *_ch;
> +	const struct list_node *_cn;
> +};
> +#define __lh(n) (((union list_head_or_node)(n))._h)
> +#define __clh(n) (((union list_head_or_node_const)(n))._h)
> +

Any reason why you don't use __attribute__ ((transparent_union)) ? I guess
this is exactly the case for which it was invented.

Cheers,
Jan

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/