This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 110b. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Adopted at the June, 2016 meeting.]
According to 9.5.1 [dcl.fct.def.general] paragraph 2,
The declarator in a function-definition shall have the form
D1 ( parameter-declaration-clause ) cv-qualifier-seqopt
ref-qualifieropt exception-specificationopt attribute-specifier-seqopt trailing-return-typeopt
However, in practice implementations accept a parenthesized declarator in a function definition.
Proposed resolution (April, 2016):
Change 9.5.1 [dcl.fct.def.general] paragraph 2 as follows:
The declarator ina function-definition shall have the form
D1 parameters-and-qualifiers trailing-return-typeopt
as described in 126.96.36.199 [dcl.fct]. A function shall be defined only in namespace or class scope.