You use an attribute-like syntax now (probably as placeholder).     However, that would be an actual alternative:   Create an attribute that the compiler (may) give a warning or an error, if the variable is modified. Advantage: Standard syntax. Ignorable.     Small issues:    - Some entity has an attribute. Attributes do not stand alone. One could just give the variable name (l-value) as an expression:   int x = 0; x = 1; [[const]] x;   - Attributes can be ignored. Overload resolution would still see the non-const x (to keep the attribute ignorable). Solution: Instead of actually making the variable const, call it   [[warn-if-modified]] x;   -----Ursprüngliche Nachricht----- Von:Bo Persson via Std-Proposals <std-proposals_at_[hidden]> Gesendet:So 16.02.2025 12:54 Betreff:Re: [std-proposals] Delayed const declaration An:std-proposals_at_[hidden]; CC:Bo Persson <bo_at_[hidden]>; On sön 2025-02-16 at 12:08, Tiago Freire via Std-Proposals wrote: > If you are going to do that, perhaps we can simplify the syntax a little > bit. > > Instead of having to declare [mutable const] which makes the variable > open for writes like any other regular variable. > > We could just omit [mutable const] and deduce that after the fact > depending on either or not a close statement is used, instead of: > > [mutable const] int x = 0; > > const x; > > you would simplify it as: > > int x = 0; > > const x; > The two-step declaration has the disadvantage that it invites typos. Or when you change the name of x, you might forget the const declaration half a page further down. Now some other x is const? This reminds me of a similar problems with goto, where added code before and after the label affects what the goto means (in a totally different location). -- Std-Proposals mailing list Std-Proposals_at_[hidden] https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals