on Thu Sep 11 2008, Joel Falcou <joel.falcou-AT-u-psud.fr> wrote:
David Abrahams a écrit :
self& operator=(self x) { swap(*this,x); return *this; }
with the rationale given in http://groups.google.com/group/comp.lang.c++.moderated/msg/5e6014446d559b63> (I suspect Andrei's CUJ article is equally good or better but much longer)
...but I would think given the thread mentioned above that answer would be self-evident, so it makes me wonder if you're trying to ask something else Sorry if i was unclear. My question was is the old operator= form still needed soemtime , thus making the 2 forms of the operator to be taught.
The only other form that makes sense for operator= doesn't use swap at all, and does things "the hard way:" destroy LHS resources and then copy the RHS resources into it. You might choose that approach if you were willing to accept the basic guarantee in order to avoid the spike in resource usage caused by having the LHS data and two copies of the RHS data all at once. The standard containers generally do it that way. -- Dave Abrahams BoostPro Computing http://www.boostpro.com