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.
Bullet 13.3 of _N4567_.5.1.1 [expr.prim.general] permits only non-static data members to appear without an object expression in an unevaluated operand. There does not appear to be a good reason to exclude non-static member functions from this permission.
Rationale (October, 2015):
Without knowing the type of this, overload resolution cannot be performed, and it seems not worth the trouble to allow member functions only in the case where there is no overloading.