On 25.04.2013, at 23:04, Marc Glisse
In any case, it could be nice to have the helpers in both directions. One addable that implements + from +=, and one addable_reverse that implements += in terms of + (you could try a+=b as a=move(a)+b maybe?).
Given that I currently have 4 overloads for operator+ that usually need a single operator+= to provide efficient operations, I'd like to see how this could work with the reverse and the use-case. Why would anyone want to implement operator+ and generate operator+= from it? And even without a detailed analysis *this=std::move(*this)+value looks and feels just wrong. Seeing something like this in the companies code-base would probably make me go to the author and ask him to fix it by reversing it. :) Of course it could be my lack of imagination and I'd be happy to see an example where it is the obvious/right approach. BR, Daniel