[Bug c++/56323] New: [C++11] cannot compile inherited constructor for typedef'ed base class

[Bug c++/56323] New: [C++11] cannot compile inherited constructor for typedef'ed base class

[t-gcc-bugzilla at snowelm dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

             Bug #: 56323
           Summary: [C++11] cannot compile inherited constructor for
                    typedef'ed base class
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: t-gcc-bugzilla@snowelm.com


Consider the following code that uses inherited constructor from a typedef'ed
type:

------------------------
struct A {
        A(int i);
};

typedef A B;

struct C : B {
        using B::B; // compile error by gcc
};

struct D : B {
        using B::A; // this is compiled as inherited constructor
};

C c(0);
D d(0);
------------------------

I believe that C should be valid, while D should be reported as invalid. 
However I cannot find anything about this problem in the C++11 standard...

In template programming, using inherited constructor is sometimes virtually
impossible, as in the following example.

------------------------
struct A {
        A(int i);
};

template <class T>
struct E {
        typedef T type;
};

template <class T>
struct F : E<T>::type {
        using E<T>::type::type; // error: E<T>::type is a typedef
};

F<A> f(0);
------------------------

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-02-14
                 CC|                            |jason at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-14 14:42:20 UTC ---
I think [class.qual]/2 says both C and D are valid.

C is valid because it is a using-declaration that is a member-declaration and
the name specified after the nested-name-specifier is the same as the
identifier in the last component of the nested-name-specifier.

D is valid because the name specified after the nested-name-specifier is the
injected-class-name of A.

In both cases the using-declaration names the constructor, so it declares a set
of inheriting constructors.

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

Jason Merrill <jason at gcc dot gnu.org> changed:

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

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2013-02-15 01:27:09 UTC ---
Author: jason
Date: Fri Feb 15 01:27:03 2013
New Revision: 196067

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196067
Log:
    PR c++/56323
    * name-lookup.c (do_class_using_decl): Handle typedefs with
    inheriting constructors.
    (push_class_level_binding_1): Allow inheriting from template
    template parameter, too.
    * pt.c (tsubst_decl) [USING_DECL]: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/inh-ctor17.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/name-lookup.c
    trunk/gcc/cp/pt.c

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |potswa at mac dot com

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-02-15 09:10:28 UTC ---
*** Bug 56333 has been marked as a duplicate of this bug. ***

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

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

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

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2013-02-15 11:17:07 UTC ---
Fixed.

[Bug c++/56323] [C++11] cannot compile inherited constructor for typedef'ed base class

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56323

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> 2013-02-27 18:13:34 UTC ---
Author: jason
Date: Wed Feb 27 18:13:24 2013
New Revision: 196316

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196316
Log:
    PR c++/56358
    PR c++/56323
    * name-lookup.c (do_class_using_decl): Use ctor_identifier instead
    of the base name for inheriting ctors.
    (push_class_level_binding_1): Remove inheriting ctor handling.
    * pt.c (tsubst_decl) [USING_DECL]: Likewise.
    * class.c (add_implicitly_declared_members): Adjust.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/inh-ctor18.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/class.c
    trunk/gcc/cp/name-lookup.c
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/g++.dg/inherit/using5.C
    trunk/gcc/testsuite/g++.old-deja/g++.other/using3.C