[Bug c++/13830] New: Invalid covariant type for identical type.

[Bug c++/13830] New: Invalid covariant type for identical type.

[mattyt-bugzilla at tpg dot com dot au]

The code below:

template < class TP >
class A {
public:
   
  friend class X;
   
  typedef X * XP;
   
  class X {};
   
  virtual XP method();
   
};
 
template < class TP >
class B : public A< TP > {
public:
   
  virtual typename A< TP >::XP method();
   
};
 
int main() {
  B<int> a;
}

gives the error in 3.4:

restor5.cc: In instantiation of `B<int>':
restor5.cc:24:   instantiated from here
restor5.cc:19: error: invalid covariant return type for `typename A<TP>::XP
B<TP>::method() [with TP = int]'
restor5.cc:11: error:   overriding `X* A<TP>::method() [with TP = int]'

as best as I can tell, the type is identical and so it should compile.

-- 
           Summary: Invalid covariant type for identical type.
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mattyt-bugzilla at tpg dot com dot au
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type.

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-01-23 16:26 -------
Confirmed. Nathan, your call! 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nathan at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-01-23 16:26:02
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-04-23 20:13 -------
Actually it looks like the problem has to do with friend classes.
If I add "class X {};" before the first template class, it works.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
   Last reconfirmed|2004-01-23 16:26:02         |2004-04-23 20:13:18
               date|                            |
            Summary|Invalid covariant type for  |Invalid covariant type for
                   |identical type.             |identical type, friend
                   |                            |related


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-04-24 05:30 -------
Of course it has to do with friend classes. In the original code, 
in the friend declaration we look up X, don't find anything, and 
inject this name in the global namespace. When we later come back 
in the derived class, we see the friend declaration again, but this 
time we seem to know that the base class also has a member class X and 
think that the friend declaration corresponded to this. 
 
If you add a global class X to the snippet, then the name injection doesn't 
have to happen, and we seem to always believe that the friend declaration 
corresponds to the global class X. 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2004-10-13 15:17 -------
Working on friend injection issues.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |lerdsuwa at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2004-12-28 15:29 -------
The patch for PR1016 will also fix this bug.  That patch is ready 
and the plan is getting it in after GCC 4.0 is branched.  I am
closing this as a duplicate.

*** This bug has been marked as a duplicate of 1016 ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |1016
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[lerdsuwa at gcc dot gnu dot org]

-- 
Bug 13830 depends on bug 1016, which changed state.

Bug 1016 Summary: [DR 166] friend class declarations not observing namespace rules.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=1016

           What    |Old Value                   |New Value
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2005-05-22 11:42 -------
Also fixed in GCC 4.0.1.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830

[Bug c++/13830] Invalid covariant type for identical type, friend related

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.0.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13830