[Bug c++/53403] New: Function template friend denied access to private types of granting template class.

[Bug c++/53403] New: Function template friend denied access to private types of granting template class.

[ibugs at qult dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

             Bug #: 53403
           Summary: Function template friend denied access to private
                    types of granting template class.
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: ibugs@qult.net


The following code compiles with GCC 4.4 but not since 4.5, until at least
4.7.0.

  template <typename T>
  class Foo {
    typedef void    type;
    template <typename U> friend void f();
  public:
    Foo() {}
  };

  template class Foo<void>;

  template <typename T>
  void f()
  {
    typedef Foo<void>::type    type;
  }

  int main()
  {
    f<void>();
  }

If the function template is declared before the definition of the class
template, or if the Foo<void> class is instantiated after f's definition, the
code compiles.  The error appears only with private types, not other private
members.

Easy to work around, but still... :/

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[ibugs at qult dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

Ignacy Gawedzki <ibugs at qult dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

Daniel Krügler <daniel.kruegler at googlemail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |daniel.kruegler at
                   |                            |googlemail dot com

--- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2012-05-18 18:27:16 UTC ---
The problem also exists for gcc 4.8.0 20120513 (experimental) with or without
activating C++11 support. Further, if the reference to the type in template f
is a dependent form, like

typedef typename Foo<T>::type type;

the error does not occur. This looks like a compiler-defect to me.

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-05-18
     Ever Confirmed|0                           |1

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-05-18 23:23:50 UTC ---
Confirmed, this possibly got broken when Jason implemented the C++11 friend
rules

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-10-04 23:06:18 UTC ---
Works in mainline. I'm adding the testcase and closing the PR.

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

--- Comment #4 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2012-10-04 23:19:52 UTC ---
Author: paolo
Date: Thu Oct  4 23:19:46 2012
New Revision: 192108

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=192108
Log:
2012-10-04  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/53403
    * g++.dg/template/friend53.C

Added:
    trunk/gcc/testsuite/g++.dg/template/friend53.C
Modified:
    trunk/gcc/testsuite/ChangeLog

[Bug c++/53403] Function template friend denied access to private types of granting template class.

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53403

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.8.0

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-10-04 23:23:42 UTC ---
Done.