[Bug c++/41972] New: static reference as a template parameter fails

[Bug c++/41972] New: static reference as a template parameter fails

[navinkumar+bugs at gmail dot com]

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in certain cases, GCC is unable to pass a static reference as a template
parameter.

SCENARIO 1 (SUCCEEDS):
//test1.cpp
template <typename T>
class X {
public:
 static const T x;
};

template <typename T>
class Y {
public:
 typedef X<T> wrapper_t;
 template <const double& _test_>
 class Foo { };
public:
 typedef Foo<wrapper_t::x> type;
};

SCENARIO 2 (FAILS):
// test2.cpp
template <typename T>
class X {
public:
    static const T x;
};

template <typename _ignore_>
class Y {
public:
    typedef X<double> wrapper_t;
    template <const double& _test_>
    class Foo { };
public:
    typedef Foo<wrapper_t::x> type;
};

template class Y<void>;

COMPILER ERROR FOR SCENARIO 2:
test2.cpp:14: error: ‘X<double>::x’ cannot appear in a constant-expression
test2.cpp:14: error: template argument 1 is invalid


-- 
           Summary: static reference as a template parameter fails
           Product: gcc
           Version: 4.4.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: navinkumar+bugs at gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] static reference as a template parameter fails

[navinkumar+bugs at gmail dot com]

------- Comment #1 from navinkumar+bugs at gmail dot com  2009-11-06 16:39 -------
Created an attachment (id=18983)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18983&action=view)
test1.cpp

test1.cpp (successfully compiles)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] static reference as a template parameter fails

[navinkumar+bugs at gmail dot com]

------- Comment #2 from navinkumar+bugs at gmail dot com  2009-11-06 16:39 -------
Created an attachment (id=18984)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18984&action=view)
test2.cpp

test2.cpp (fails to compile)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2009-11-06 17:22 -------
Confirmed, a reduced testcase:
struct X {
  static const double  x;
};
template <const double& _test_>
  class Foo { };
template <typename _ignore_>
struct Y {
  typedef Foo<X::x> type;
};

--- CUT ---
If Y is a non template, it works which makes me think we are not binding X::x
to the reference type.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |rejects-valid
      Known to fail|                            |4.0.1 4.4.0 4.5.0
      Known to work|                            |3.3
   Last reconfirmed|0000-00-00 00:00:00         |2009-11-06 17:22:18
               date|                            |
            Summary|static reference as a       |[4.3/4.4/4.5 Regression]
                   |template parameter fails    |nondependent static member
                   |                            |function as a reference
                   |                            |template parameter fails
   Target Milestone|---                         |4.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[jason at gcc dot gnu dot org]

-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jason at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2009-11-06 17:22:18         |2009-11-09 15:27:58
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[jason at gcc dot gnu dot org]

------- Comment #4 from jason at gcc dot gnu dot org  2009-11-09 18:33 -------
Subject: Bug 41972

Author: jason
Date: Mon Nov  9 18:32:53 2009
New Revision: 154042

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=154042
Log:
        PR c++/41972
        * parser.c (cp_parser_template_argument): Accept SCOPE_REF around
        VAR_DECL.

Added:
    trunk/gcc/testsuite/g++.dg/template/ref4.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/parser.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[jason at gcc dot gnu dot org]

------- Comment #5 from jason at gcc dot gnu dot org  2009-11-09 20:28 -------
Subject: Bug 41972

Author: jason
Date: Mon Nov  9 20:28:18 2009
New Revision: 154050

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=154050
Log:
        PR c++/41972
        * parser.c (cp_parser_template_argument): Accept SCOPE_REF around
        VAR_DECL.

Added:
    branches/gcc-4_4-branch/gcc/testsuite/g++.dg/template/ref4.C
Modified:
    branches/gcc-4_4-branch/gcc/cp/ChangeLog
    branches/gcc-4_4-branch/gcc/cp/parser.c
    branches/gcc-4_4-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[jason at gcc dot gnu dot org]

------- Comment #6 from jason at gcc dot gnu dot org  2009-11-09 22:01 -------
Subject: Bug 41972

Author: jason
Date: Mon Nov  9 22:01:09 2009
New Revision: 154053

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=154053
Log:
        PR c++/41972
        * parser.c (cp_parser_template_argument): Accept SCOPE_REF around
        VAR_DECL.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/g++.dg/template/ref4.C
Modified:
    branches/gcc-4_3-branch/gcc/cp/ChangeLog
    branches/gcc-4_3-branch/gcc/cp/parser.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972

[Bug c++/41972] [4.3/4.4/4.5 Regression] nondependent static member function as a reference template parameter fails

[jason at gcc dot gnu dot org]

------- Comment #7 from jason at gcc dot gnu dot org  2009-11-09 22:02 -------
Fixed.


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41972