On 6/11/2010 12:36 PM, Eric Niebler wrote:
On 6/11/2010 12:27 PM, David Abrahams wrote:
At Fri, 11 Jun 2010 12:12:27 -0400, Eric Niebler wrote
makes it by-val. Under the hood, Phoenix would actually be storing every captured variable both by value and by reference.
!! Sounds expensive.
The plan has always been to make capture-by-value the default. Saving off a reference as well is free.
Well, there's a hitch. ref[ bigobj += _1 ] Users might reasonably expect this to not make a copy of bigobj, and the way to avoid it is not obvious: ref[ ref(bigobj) += _1 ] Clearly the user has already stated their intention to capture bigobj by reference and shouldn't have to say it again. I think default capture modes may be unworkable if we want the default mode to be by-value. -- Eric Niebler BoostPro Computing http://www.boostpro.com