This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Accepted as a DR at the June, 2023 meeting.]
126.96.36.199 [dcl.ref] paragraph 1 specifies:
A declarator that specifies the type “reference to cv void” is ill-formed.
A declarator does not contain the leading decl-specifier-seq of a declaration, so the following example is not covered by the prohibition:
void f(void& x);
Proposed resolution (approved by CWG 2023-06-15):
Change in 188.8.131.52 [dcl.ref] paragraph 1 as follows:
A declarator that specifiesthe type “reference to cv void” is ill-formed.