On 1/22/2011 10:13 PM, Thomas Heller wrote:
Joel de Guzman wrote:
On 1/22/2011 9:02 PM, Joel de Guzman wrote:
On 1/22/2011 8:17 PM, Thomas Heller wrote:
Joel de Guzman wrote:
On 1/21/2011 8:39 PM, Michel MORIN wrote:
I have another question about Phoenix 3. Is the copy assignment of Actors no-op, or does it really copy the contents?
Actor a; Actor b = ...; a = b; // no-op?
It should copy the contents. Thomas?
Not really. It needs to create the assign actor (that means the expression template representing the assignment operation. It is neither a no-op nor is the assignment "executed". Remember the stuff about phoenix being lazy ;)?
No! That's not the case here. There *is* still the immediate assignment operator being called when two actors are of the same type (e.g. when lhs and rhs are phoenix values). In these cases, a *is* assigned to *b*. Thus, for values, the contents are copied. Ditto for copy construction of course.
Oops, I meant b is assigned to a of course :-P
Seems like i don't stand a chance. I was trying to find a use case where you might want the lazy version of the assignment ... couldn't find one. Added the operator=(actor const&) to phoenix 3.
Thanks for the hint.
BTW, don't forget to add the non-const overload as well. Proto is pretty finicky about this: operator=(actor& rhs) I know.. I've been there (with Spirit rules). If you don't do that, and your rhs is non-const, you'll get a lazy treatment! LOL :P Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com