Non-defining object declarations can have type cv void CWG2475

[sdkrystian]

Nothing prohibits an object declaration from having type cv void. While there is wording that prevents an object definition from having such a type in [basic.def], so such wording exists to cover the following:

extern void var; // not a definition, so incomplete type is permitted

[jensmaurer]

While pretty obvious, this does not feel editorial to me.

[dcl.pre] p10 introduces "object declaration" (which, curiously enough, might also declare a reference). This would be a suitable place to prohibit "cv void".

[jensmaurer]

CWG 2020-12-07:
C allows extern void var;
A new core issue will be created, and deferred to the WG14/WG21 liaison group.

[jensmaurer]

[basic.pre] p6

A variable is introduced by the declaration of a reference other than a non-static data member or of an object. The variable’s name, if any, denotes the reference or object.

Presumably, an "object" must have object type.

[jensmaurer]

See CWG2475

[frederick-vs-ja]

Should have been resolved by #6118 (4682d95).