This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 115d. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.

2024-10-26

2582. Differing member lookup from nested classes

[Accepted at the July, 2022 meeting.]

Consider:

  typedef int T;
  struct A {
   struct B {
    static T t;
   };
   typedef float T; // IFNDR?
  };

Subclause 6.5.2 [class.member.lookup] paragraph 6 specifies:

The result of the search is the declaration set of S(N, T). If it is an invalid set, the program is ill-formed. If it differs from the result of a search in T for N from immediately after the class-specifier of T, the program is ill-formed, no diagnostic required.

It is unclear whether the lookup of T inside A::B is subject to the "if it differs" rule, given that the class-specifier of A::B ends before introducing A::T.

Proposed resolution (approved by CWG 2022-05-06):

Change in 6.5.2 [class.member.lookup] paragraph 6 as follows:

If it differs from the result of a search in T for N from immediately after the class-specifier in a complete-class context of T, the program is ill-formed, no diagnostic required.