I know there’ve been several discussions about this topic but I actually can’t find any of them, for which I mostly blame the discourse search tool :P Please edit this post with links to others if you know of some.
I was just reading about Eigen and saw there’s an alternative to the templated Eigen Dense approach to not generating temporaries, and that’s to use Eigen::Ref: http://eigen.tuxfamily.org/dox/TopicFunctionTakingEigenTypes.html#TopicUsingRefClass
Did anyone try this? Does it perform almost as well? It looks like the kind of thing that we could actually start using immediately, which is a serious pro when compared with the more-perfect but much-more-work approach of retemplating everything to use the eigen base class and calling .eval() judiciously.