On Thursday, 14 February 2013 at 20:53:26 UTC, Jonathan M Davis
wrote:
And Walter and Andrei both seem to think that having expensive
postlbits is a
design mistake. The range stuff sort of tries to support it
with the move*
primitives, but Andrei's been wanting to argue for just
assuming that
postblits are cheap. And Walter was actually arguing at one
point for making
it illegal (probably by getting rid of postblit all together -
I don't
remember the details). Plenty of the rest of us don't agree,
but to some
extent, it is true that having an expensive postblit is asking
for it. On a
related note, we still need a solution for dealing with const
postblits
(probably be introducing copy constructors - IIRC Andrei was
considering
phasing out postblits in favor of copy constructors, which
would be
unnecessary, but we do need a way to deal with deep copying
const structs
which hold reference types which need to be deep copied.
When you say things like "Andrei was considering phasing out
postblits..." I get nervous. Can we please have some comments
from Andrei/Walter about what the plans are? I'm not asking for
the ultimate solution - just to know the general direction and
where this issue stands at present. Is there anything any of us
can do to help move this forward?
Regarding replacing expensive postblits with copy constructors -
how does that help? The expense will remain the same - if you
need a transitive copy, you need a transitive copy.
Thanks
Dan
