Re: [Qemu-devel] Re: [PATCH 0/9] Virtio cleanups

[Jamie Lokier]

Michael S. Tsirkin wrote:
> That's version 1 of my patch. Version 2 removed even need for macro
> completely by moving allocations to the caller.

The downside of moving allocations are: (1) it's one more call in the
caller, to allocate the type, (2) it needs a virtual destructor for
each type to free the object, which can clutter the code if there is
no other reason for virtual destructors.

I don't think those are necessarily bad, but they can remove from the
neatness of existing code.  Personally I favour an occasional macro
using sizeof/offsetof/container_of if the result is a natural and
sensible API to all of its callers.

-- Jamie