With RVO we would not need copy or move. -----Ursprüngliche Nachricht----- Von:SD SH via Std-Proposals <std-proposals_at_[hidden]> Gesendet:Di 21.10.2025 14:02 Betreff:Re: [std-proposals] Forwarding Reference can also accept PRvalue (not just Lvalue or Rvalue) An:std-proposals_at_[hidden]; CC:SD SH <Z5515zwy_at_[hidden]>; Then how will you implement it? Think of this: ``` SYSCLASS struct Accessor; // unmovable and uncopyable extern SYSAPI Accessor (*access)(); int main() { StoreAndGet<Accessor>(access()); } ``` We don't know what the function will do, and it's impossible to change the function. We only know that access() will construct a Accessor object and follow the calling convention, then we must call copy or move constructor, but in this case we can't do it. For your example, if a function returns a unmovable and uncopyable object means that you shouldn't construct it by existing objects in your code.