On Thu, Sep 11, 2008 at 11:06 AM, Thorsten Ottosen <thorsten.ottosen@dezide.com> wrote:

Gevorg Voskanyan skrev:

...

Giovanni Piero Deretta wrote:

...

If you do not want to deal with move emulation (which I've found very brittle in complex expressions), a simple way to to gain the advantage of T::operator=(T rhs) even when assigning from lvalues is something like:

templateT destructive_copy(T& x) { using std::swap; T result; swap(result, x); return x; }

which relies on NRVO to eliminate expensive copies:

I think the best way (= most RVOs) to write the assignment operator is to take the T argument by value.

Uh? I do not understand how your statement relates to the code above. The point of destructive_copy is to move out of lvalues (by 'converting' them to rvalues), not optimizing out copies of rvalues. -- gpd