cplusplus / cplusplus/draft

Two conflict notes about member lookup occurred in base-specifier

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Description

@opensdh
[basic.scope.class#note-1]

[Note 1: Lookup from a program point before the class-specifier of a class will find no bindings in the class scope.

[Example 1:
  
      template < class D >
      struct B {
         D::type x; // #1
      };
      struct A { using type = int; };
      struct C : A, B< C > {}; // error at #1: C​::​type not found.

— end example]

— end note]

The note and the example state that the member lookup from a program point P at a base-specifier cannot find any member.

However, the note [class.member.lookup#note-2] gives a different conclusion, that is

[Note 2: If T is incomplete, only base classes whose base-specifier appears before P are considered. If T is an instantiated class, its base classes are not dependent. — end note]

It seems like the base class A could be considered since it appears before point P in B<C>. In addition, except that P occurs in "base-specifier-list", I cannot figure out a case that there is a base class that can appear after P.

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Research direction

Start by reading [basic.scope.class#note-1] and [class.member.lookup#note-2] in the draft, including the cited base-specifier example. Compare their lookup rules and determine what wording or example change would reconcile the apparent conflict; done means the two notes give consistent conclusions.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, tex
Domain
documentation
Issue type
Documentation
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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