[Bug c++/48920] New: typename specifier should not ignore non-type names

[Bug c++/48920] New: typename specifier should not ignore non-type names

[schaub.johannes at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

           Summary: typename specifier should not ignore non-type names
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: schaub.johannes@googlemail.com


The following is ill-formed code

    struct A {
      struct B { };
      int B;
    };

    typename A::B a;

GCC accepts it. As a perhaps related issue, the following looks well-formed:

    template<typename T>
    void f(typename T::B) { }

    template<typename T>
    void f(struct T::B) { }

GCC rejects it as a redefinition. The dependent parameter types of both look
different.

[Bug c++/48920] typename specifier should not ignore non-type names

[schaub.johannes at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

--- Comment #1 from Johannes Schaub <schaub.johannes at googlemail dot com> 2011-05-06 23:47:33 UTC ---
(In reply to comment #0)
> […] As a perhaps related issue, the following looks well-formed:
> 
>     template<typename T>
>     void f(typename T::B) { }
> 
>     template<typename T>
>     void f(struct T::B) { }
> 
> GCC rejects it as a redefinition. The dependent parameter types of both look
> different.

The Itanium ABI does not include any way to distinguish these two cases, so I
suspect GCC can do nothing about this. And if one were to include "typename" as
a hint into the mangling, I can see how this quickly can get out of hand.

[Bug c++/48920] typename specifier should not ignore non-type names

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-12-26 13:21:27 UTC ---
For the first testcase [basic.scope.class] says no diagnostic required, doesn't
it?

[Bug c++/48920] typename specifier should not ignore non-type names

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |michele.caini at gmail dot com

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
*** Bug 78286 has been marked as a duplicate of this bug. ***

[Bug c++/48920] typename specifier should not ignore non-type names

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Hmm, MSVC rejects this for a different reason from clang (and a different
reason from what the report is requesting):
<source>(7): error C2761: 'int A::B': redeclaration of member is not allowed

[Bug c++/48920] typename specifier should not ignore non-type names

[schaub.johannes at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

--- Comment #6 from Johannes Schaub <schaub.johannes at googlemail dot com> ---
Well then you can replace the class with a nameepace, I think, to remove the
class-scope complication. I think GCC would still incorrectly apply typename
lookup.

[Bug c++/48920] typename specifier should not ignore non-type names

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-12-08
             Status|UNCONFIRMED                 |NEW

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed with:
    namespace A {
      struct B { };
      int B;
    };

    typename A::B a;

[Bug c++/48920] typename specifier should not ignore non-type names

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48920

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup of bug 32066.

*** This bug has been marked as a duplicate of bug 32066 ***