To make the default argument unique (regardless of declaration), the paper states:     10 Reflecting on Parameter Default Values For completeness sake, we are mentioning default values for parameters. In our research, we have encountered the need to know whether a parameter has a default value, but not necessarily what the value is. Since the language forbids redeclaration of the same function with a default value for the same parameter, there is no ambiguity. Therefore, we only propose to add the has_default_argument as it was already in [P1240R2].     Which does not necessarily preclude additional research and an addition for C++29.   -----Ursprüngliche Nachricht----- Von:Ville Voutilainen via Std-Proposals <std-proposals_at_[hidden]> Gesendet:Mi 05.03.2025 15:57 Betreff:Re: [std-proposals] std::function with default arguments An:std-proposals_at_[hidden]; CC:Ville Voutilainen <ville.voutilainen_at_[hidden]>; On Wed, 5 Mar 2025 at 16:51, Thiago Macieira via Std-Proposals <std-proposals_at_[hidden]> wrote: > > On Wednesday, 5 March 2025 06:18:17 Pacific Standard Time Frederick Virchanza > Gotham wrote: > > It's a bit of a mammoth, but I gave it a scroll through. Unless I've > > missed something, I don't see any part where you can get a function's > > default arguments. > > That would be the answer I'm looking for. https://wg21.link/p3096 is the paper you're looking for. It's been approved by EWG and should progress into spec reviews. -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals