[Bug c++/60786] New: In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[Bug c++/60786] New: In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60786

            Bug ID: 60786
           Summary: In C++11 an explicit instantiation with an unqualified
                    name must be in the right namespace
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Keywords: accepts-invalid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: redi at gcc dot gnu.org

This should not be accepted in C++11 mode:

namespace A {
  template<typename T> struct B { };
}

using A::B;
template class B<int>;


[temp.explicit] p3:
"An explicit instantiation shall appear in an enclosing namespace of its
template. If the name declared in the explicit instantiation is an unqualified
name, the explicit instantiation shall appear in the namespace where its
template is declared or, if that namespace is inline (7.3.1), any namespace
from its enclosing namespace set."

This is a change from C++03:

"A definition of a class template or class member template shall be in scope at
the point of the explicit instantiation of the class template or class member
template."

[Bug c++/60786] In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60786

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Author: redi
Date: Tue Apr 15 19:05:45 2014
New Revision: 209431

URL: http://gcc.gnu.org/viewcvs?rev=209431&root=gcc&view=rev
Log:
    PR c++/60786
    * testsuite/20_util/shared_ptr/requirements/explicit_instantiation/
    1.cc: Fix invalid explicit instantiations with unqualified names.
    * testsuite/20_util/shared_ptr/requirements/explicit_instantiation/
    2.cc: Likweise.
    * testsuite/20_util/tuple/53648.cc: Likweise.
    * testsuite/20_util/weak_ptr/requirements/explicit_instantiation/1.cc:
    Likewise.
    * testsuite/20_util/weak_ptr/requirements/explicit_instantiation/2.cc:
    Likewise.
    * testsuite/23_containers/unordered_map/requirements/
    debug_container.cc: Likewise.
    * testsuite/23_containers/unordered_map/requirements/
    explicit_instantiation/3.cc: Likewise.
    * testsuite/23_containers/unordered_multimap/requirements/debug.cc:
    Likewise.
    * testsuite/23_containers/unordered_multimap/requirements/
    explicit_instantiation/3.cc: Likewise.
    * testsuite/23_containers/unordered_multiset/requirements/debug.cc:
    Likewise.
    * testsuite/23_containers/unordered_multiset/requirements/
    explicit_instantiation/3.cc: Likewise.
    * testsuite/23_containers/unordered_set/requirements/
    debug_container.cc: Likewise.
    * testsuite/23_containers/unordered_set/requirements/
    explicit_instantiation/3.cc: Likewise.

Modified:
    trunk/libstdc++-v3/ChangeLog
   
trunk/libstdc++-v3/testsuite/20_util/shared_ptr/requirements/explicit_instantiation/1.cc
   
trunk/libstdc++-v3/testsuite/20_util/shared_ptr/requirements/explicit_instantiation/2.cc
    trunk/libstdc++-v3/testsuite/20_util/tuple/53648.cc
   
trunk/libstdc++-v3/testsuite/20_util/weak_ptr/requirements/explicit_instantiation/1.cc
   
trunk/libstdc++-v3/testsuite/20_util/weak_ptr/requirements/explicit_instantiation/2.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/debug_container.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/explicit_instantiation/3.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/debug.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/explicit_instantiation/3.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/debug.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/explicit_instantiation/3.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/debug_container.cc
   
trunk/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/explicit_instantiation/3.cc

[Bug c++/60786] In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60786

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I've fixed the libstdc++ tests so they don't rely on this bug

[Bug c++/60786] In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[ville.voutilainen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60786

Ville Voutilainen <ville.voutilainen at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2014-12-14
                 CC|                            |ville.voutilainen at gmail dot com
     Ever confirmed|0                           |1
      Known to fail|                            |4.8.2, 4.9.1, 5.0

--- Comment #3 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
Clang rejects the code.

[Bug c++/60786] In C++11 an explicit instantiation with an unqualified name must be in the right namespace

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60786

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
   Target Milestone|---                         |7.0
         Resolution|---                         |DUPLICATE

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
In GCC7+, we started having a pedantic warning (only with -pedantic or
-Wpedantic):
<source>:6:16: warning: explicit instantiation of 'template<class T> struct
A::B' outside its namespace must use a nested-name-specifier [-Wpedantic]
 template class B<int>;
                ^~~~~~

This is a dup of bug 56480.

*** This bug has been marked as a duplicate of bug 56480 ***