https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51571
marc at kdab dot com changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |marc at kdab dot com --- Comment #4 from marc at kdab dot com --- I would like to strongly oppose the notion that this "just a missed optimisation and not very critical, really". NRVO is not just "an optimisation". It's actually one that is explcitly permitted to change observable behaviour of the program and it's extremely powerful. And it it _required_ for performant C++. Just try to return a std::vector by value to see the importance of this optimisation. This is not missed optimisation. This is premature pessimisation. You could just as well stop all optimisation work for the C++ frontend until this is implemented, because any other optimisation effords are dwarfed by the overhead when NRVO is expected by the developer but not applied. Please make this a top priority. Every C++ program will benefit both in text size and in runtime performance - dramatically.