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Date: Fri, 09 Dec 2011 12:26:10 +0100
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v2 15/18] rtc: add a dynamic property for
 retrieving the date
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To: Anthony Liguori <aliguori@us.ibm.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, Jan Kiszka <jan.kiszka@siemens.com>, qemu-devel@nongnu.org, Luiz Capitulino <lcapitulino@redhat.com>, Gerd Hoffman <kraxel@redhat.com>, Markus Armbruster <armbru@redhat.com>

Am 02.12.2011 21:20, schrieb Anthony Liguori:
> This really shows the power of dynamic object properties compared to qdev
> static properties.
> 
> This property represents a complex structure who's format is preserved over the
> wire.  This is enabled by visitors.
> 
> It also shows an entirely synthetic property that is not tied to device state.
> 
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

There's one thing that I was hoping to find answered when I would have
reviewed the whole series, but it hasn't happened: There is no doubt
that dynamic properties (in the sense of being able to modify them after
constructions) are a useful thing. But you also claim that class-based
properties are not enough for QOM and that we need object-based ones,
which is a requirement not immediately obvious to me.

Can you provide some examples where we would explicitly need
object-based properties?

Kevin