Hum, this could be useful if combined with other features.
Something that I want is to be able to make const a variable that is originally not declared const.

Maybe we could have a "shadowing" specifier, that could do that.

Like
shadow(const) var; //makes var const for the remainder of the scope.
shadow(void) var; //makes var inaccessible

I can also see the feature being used as.

class A{};
class B: public A{};
B var;

shadow(const A&) var; //var is still an object of type B but only accessible as an object of parent type A.

I'm not so sure about this last one.


From: Std-Proposals <std-proposals-bounces@lists.isocpp.org> on behalf of Ville Voutilainen via Std-Proposals <std-proposals@lists.isocpp.org>
Sent: Tuesday, August 11, 2026 9:13:23 PM
To: std-proposals@lists.isocpp.org <std-proposals@lists.isocpp.org>
Cc: Ville Voutilainen <ville.voutilainen@gmail.com>
Subject: Re: [std-proposals] A new C++ keyword: forget

On Tue, 11 Aug 2026 at 22:11, Henry Skoglund via Std-Proposals
<std-proposals@lists.isocpp.org> wrote:
>
> On 2026-08-11 21:05, Simon Schröder wrote:
> > This reminds me (in case you are continuing with the proposal): You should discuss if once a variable has been poisoned, if the same name can be reused for a different variable.
> Hi, once poisoned I think it should not be allowed to be reused. I.e.
> issue a compiler error like:
>      double raw;
>      forget raw;
>      int raw;   // <--- error: raw is forgotten and cannot be resurrected

Exactly. Make name lookup still find the name, but make it an error to
find a poisoned name.
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