sort was just an example.   Should generic algorithms prefer swap, when possible?     -----Ursprüngliche Nachricht----- Von:Jason McKesson via Std-Proposals <std-proposals_at_[hidden]> Gesendet:Mi 29.10.2025 20:02 Betreff:Re: [std-proposals] Replace an object -- but retain old object if new object fails to construct An:std-proposals_at_[hidden]; CC:Jason McKesson <jmckesson_at_[hidden]>; On Wed, Oct 29, 2025 at 1:58 PM Sebastian Wittmeier via Std-Proposals <std-proposals_at_[hidden]> wrote: > > So the aim would be that there is as few code as possible to rely on type 2. > > Most code with relocatibility should be generic enough not to care about it. > > > > However, for algorithms one would want to estimate the cost. > > > > For example let's sort some objects of type T with small size <= 8. > > Should we move around indices or pointers, or should we directly sort the objects? Would a sorting algorithm need to care about relocation, though? Can you make a type for which relocation is noexcept but swapping can't be noexcept? Since the sorting algorithm is operating on a group of objects in-situ, it shouldn't need to relocate anything at all. > -----Ursprüngliche Nachricht----- > Von: Jason McKesson via Std-Proposals <std-proposals_at_[hidden]> > Gesendet: Mi 29.10.2025 18:17 > Betreff: Re: [std-proposals] Replace an object -- but retain old object if new object fails to construct > An: std-proposals_at_[hidden]; > CC: Jason McKesson <jmckesson_at_[hidden]>; > On Wed, Oct 29, 2025 at 12:50 PM Sebastian Wittmeier via Std-Proposals > <std-proposals_at_[hidden]> wrote: > > > Note that "type 1" represents types that can't be relocated at all. So > such code should fail to compile. But yes, the same interface that's > used to relocate type 3&4 should also be performance-friendly for type > 2 cases. The only time you need to care about type 2 as a distinct > possibility is if you're relying on low-level bit fiddling. > > > > -- > Std-Proposals mailing list > Std-Proposals_at_[hidden] > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals