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Subject: Re: [Qemu-devel] [PATCH 08/14] qapi: convert eject (qmp and hmp) to
 QAPI
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To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org, Michael Roth <mdroth@linux.vnet.ibm.com>, Luiz Capitulino <lcapitulino@redhat.com>

On 08/25/2011 04:52 PM, Kevin Wolf wrote:
> >
> >  It's not pretty, but it lets us preserve compatibility.  I think it's
> >  also safer for dealing with pointers because otherwise you have a mix of
> >  pointers that may be null and may not be null.  Having a clear
> >  indication of which pointers are nullable makes for safer code.
>
> I'm not saying that implementing a default value in generic (or
> generated) code works for all cases. But if the schema supported default
> values, we could get rid of the parameter in all simple cases (which I
> would expect to be the majority); and if there is no default value in
> the schema, we could still generate the has_* parameters.
>

An alternative is to pass a struct by value, with a .valid bool followed 
by the actual value (which should be initialized even if not valid, just 
to be safe).

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.