Are value types supposed to work at all currently?

Vitaly Davidovich vitalyd at
Thu May 21 14:19:02 UTC 2015

Hi Simon,

On the 1st slide that talks about object overhead, it may be worthwhile to
mention that the overhead stated there is for 32bit.  On 64bit, the header
is either 12 or 16 bytes, depending on whether compressed oops are used or
not (in the case of 12 bytes with compressed oops, the 4 byte alignment gap
can be used to lay out a suitable field in there as well, AFAIK).  Also,
that's Hotspot specific, other JVMs can use different representation/layout.

On Thu, May 21, 2015 at 10:03 AM, Simon Ochsenreither <
simon at> wrote:

> Hi Brian, hi Maurizio,
> here are the slides I used for my talk yesterday:
> I hope they accurately reflected the current situation as much as possible.
> Corrections and comments welcome! (The talk at ScalaDays will likely look
> quite differently, though.)
> I finished the slides a few minutes before the talk, so they are quite
> rough.
> One thing I would certainly add are all the boxing considerations, which
> were discussed at the meetup, but are missing on the slides.
> Thanks!
> Bye,
> Simon

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