[expr.reflect] Clarify whether the protected access rule for a pointer-to-member applies to a reflect-expression

[t3nsor]

Full name of submitter: Aurelien Cassagnes

Issue description: It is not clear whether the following is valid:

class A {
protected:
  void f();
};

struct B : A {
    static constexpr auto r = ^^A::f;
};

According to [expr.reflect]/7.2, "overload resolution for the expression" &A::f "with no target shall select a unique function". Do the restrictions in [class.protected] on the use of the expression &A::f apply to the reflect-expression?

Suggested resolution (by Brian): Edit [expr.reflect]/7.2 as follows:

Otherwise, if the id-expression denotes an overload set S, overload resolution for the expression &S with no target shall select a unique function ([over.over])the expression & id-expression shall be well-formed when considered as an unevaluated operand; R represents that the function selected by overload resolution ([over.over]).