This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See for the official list.


42. Redefining names from base classes

Section: 6.4.7  [basic.scope.class]     Status: NAD     Submitter: Steve Clamage     Date: 15 Sep 1998

Consider this code:

    struct Base {
        enum { a, b, c, next };

    struct Derived : public Base {
        enum { d = Base::next, e, f, next };

The idea is that the enumerator "next" in each class is the next available value for enumerators in further derived classes.

If we had written

    enum { d = next, e, f, next };

I think we would run afoul of 6.4.7 [basic.scope.class] :
A name N used in a class S shall refer to the same declaration in its context and when re-evaluated in the completed scope of S. No diagnostic is required for a violation of this rule.
But in the original code, we don't have an unqualified "next" that refers to anything but the current scope. I think the intent was to allow the code, but I don't find the wording clear on on that point.

Is there another section that makes it clear whether the original code is valid? Or am I being obtuse? Or should the quoted section say "An unqualified name N used in a class ..."?

Rationale (04/99): It is sufficiently clear that "name" includes qualified names and hence the usual lookup rules make this legal.