[Bug c++/100084] New: using enum lookup isn't type-only

[Bug c++/100084] New: using enum lookup isn't type-only

[barry.revzin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100084

            Bug ID: 100084
           Summary: using enum lookup isn't type-only
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: barry.revzin at gmail dot com
  Target Milestone: ---

>From Stack Avarflaw (https://stackoverflow.com/q/67096550/2069064):

namespace A { enum A {}; };
using namespace A;
using enum A;

gcc trunk rejects this lookup as ambiguous, between the namespace A and the
enum A. But our lookup in this context should be type-only, so the namespace A
should not a candidate.

[Bug c++/100084] using enum lookup isn't type-only

[barry.revzin at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100084

--- Comment #1 from Barry Revzin <barry.revzin at gmail dot com> ---
Also gcc accepts:

namespace A { enum A {}; };
using namespace A;
using enum A::A;

Which, apparently, this one should actually be ambiguous.

[Bug c++/100084] using enum lookup isn't type-only

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100084

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
                 CC|                            |mpolacek at gcc dot gnu.org
           Keywords|                            |accepts-invalid,
                   |                            |rejects-valid
   Last reconfirmed|                            |2021-04-14

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.

[Bug c++/100084] using enum lookup isn't type-only

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100084

康桓瑋 <hewillk at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hewillk at gmail dot com

--- Comment #3 from 康桓瑋 <hewillk at gmail dot com> ---
Here is a weird case that I think should be accepted:

enum e { e };
using enum e;

gcc rejects with:

<source>:2:12: error: 'e' is not a type
    2 | using enum e;
      |            ^

[Bug c++/100084] using enum lookup isn't type-only

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100084

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |luizfvalle at pm dot me

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 103824 has been marked as a duplicate of this bug. ***