Def a qualified yes. The pass by value will often allow the compiler to deal with less as a pass by ref/ptr makes it more pessimistic. You see this play out i

Def a qualified yes. The pass by value will often allow the compiler to deal with less as a pass by ref/ptr makes it more pessimistic. You see this play out in trying to get the auto-vectorizer going by copying N values to a local buffer in the loop prior to operating in them. The optimizer in c++ compilers are really good at inlining and if it's a single TU more so. So the size isn't the issue in those cases too. In addition, on the other size most optimizers have a form of return value optimization that elides the copy/move on the return value. Where they often get hit up or lacking is heap allocations. They seem to hide a lot and only some compilers can elide a heap allocation. Use after move is interesting. Many cases of move are not necessary anyways (returning an automatic storage object) but the complexity of the code already would be on part with using std::move. I don't think an optimizer will do that one even if it is that last usage.