[Bug c++/21682] Disallowed using declaration

[Bug c++/21682] Disallowed using declaration

[pcarlini at suse dot de]

------- Comment #3 from pcarlini at suse dot de  2006-03-10 09:38 -------
*** Bug 26605 has been marked as a duplicate of this bug. ***


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pcarlini at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pcarlini at suse dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[jason at gcc dot gnu dot org]

------- Comment #4 from jason at gcc dot gnu dot org  2009-03-03 19:34 -------
This is core issue 565, which has not been addressed by the committe, though
John's comment makes sense to me.  How important is this issue to SFINAE
techniques?


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jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[dave at boost-consulting dot com]

------- Comment #5 from dave at boost-consulting dot com  2009-03-03 21:11 -------
I don't know that SFINAE has anything to do with this.  Looks like I was just
doing namespace composition.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[jason at gcc dot gnu dot org]

------- Comment #6 from jason at gcc dot gnu dot org  2009-03-03 22:31 -------
The names in 26605 make it clearer that it's about SFINAE, but that seems to be
what your testcase is trying to do as well: if the compiler accepts the using,
you would end up with an ambiguous call except that one of the templates is
discarded because only one of the templates has a nested type named "type" for
int or double arguments.

I don't see any reason why you would want to have multiple templates with the
same parameters unless you were using SFINAE to remove all but one of them
during the deduction phase of overload resolution.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |paolo.carlini at oracle dot com
   Target Milestone|---                         |4.9.0

--- Comment #7 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Mine.

[Bug c++/21682] Disallowed using declaration

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

--- Comment #8 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> ---
Author: paolo
Date: Mon Sep  2 09:42:39 2013
New Revision: 202163

URL: http://gcc.gnu.org/viewcvs?rev=202163&root=gcc&view=rev
Log:
/cp
2013-09-02  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/21682, implement DR 565
    * name-lookup.c (compparms_for_decl_and_using_decl): New.
    (push_overloaded_decl_1, do_nonmember_using_decl): Use it.

/testsuite
2013-09-02  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/21682, implement DR 565
    * g++.dg/template/using24.C: New.
    * g++.dg/template/using25.C: Likewise.
    * g++.dg/template/using26.C: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/template/using24.C
    trunk/gcc/testsuite/g++.dg/template/using25.C
    trunk/gcc/testsuite/g++.dg/template/using26.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/name-lookup.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/21682] Disallowed using declaration

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
                 CC|gcc-bugs at gcc dot gnu.org,       |
                   |paolo.carlini at oracle dot com    |
            Version|4.0.0                       |4.9.0
         Resolution|---                         |FIXED

--- Comment #9 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Done for 4.9.0.

[Bug c++/21682] New: Disallowed using declaration

[dave at boost-consulting dot com]

GCC reports
  ../../../../boost/sequence/begin.hpp:53: error: 'begin' is already declared in
this scope

When creating an overload set by bringing a function into a namespace via
using-declaration.  Compile the enclosed source to demonstrate.

-- 
           Summary: Disallowed using declaration
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dave at boost-consulting dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[dave at boost-consulting dot com]

------- Additional Comments From dave at boost-consulting dot com  2005-05-20 17:13 -------
Created an attachment (id=8939)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8939&action=view)
preprocessed source


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682

[Bug c++/21682] Disallowed using declaration

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-05-21 14:35 -------
Confirmed, reduced testcase (which shows the problem):
template <class T>
struct t
{
  typedef typename T::type type;
};
template<> class t<int>{};

template <class T> struct t1{ };
template<> struct t1<int>
{
  typedef int type;
};

namespace name1
{
  template <class S> typename t<S>::type begin(S const& s);
  namespace name2
  {
    template <class S> typename t1<S>::type begin(S const& s);
  }
  using name2::begin;
}

/* Test calling the function. */
int f(int a) { return name1::begin(a); }

struct aa { typedef double type; };
double g(aa t) { return name1::begin(t); }

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |rejects-valid
   Last reconfirmed|0000-00-00 00:00:00         |2005-05-21 14:35:40
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21682