[Bug c++/50372] New: c++11: pointers to static functions should be valid template parameters

[Bug c++/50372] New: c++11: pointers to static functions should be valid template parameters

[luto at mit dot edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50372

             Bug #: 50372
           Summary: c++11: pointers to static functions should be valid
                    template parameters
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: luto@mit.edu


Created attachment 25253
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25253
Test case

In n3242 [temp.arg.nontype]:

A template-argument for a non-type, non-template template-parameter shall be
one of:
...
 - a constant expression (5.19) that designates the address of an object with
static storage duration and external or internal linkage or a function with
external *or internal* linkage, ...  [emphasis added]

Nonetheless, the attached test case fails to compile with:

foo.cc: In function ‘void test()’:
foo.cc:8:21: error: ‘static_func’ is not a valid template argument for type
‘void (*)()’ because function ‘void static_func()’ has not external linkage
foo.cc:8:21: error: no matching function for call to ‘foo()’
foo.cc:8:21: note: candidate is:
foo.cc:2:6: note: template<void (* fptr)()> void foo()
foo.cc:2:6: note:   substitution of deduced template arguments resulted in
errors seen above

even with -std=gnu++0x.  Tested on 4.6.0 and trunk r178795.

AFAICT the error is correct in c++98 mode.

[Bug c++/50372] [C++0x] pointers to static functions should be valid template parameters

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50372

--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-11 04:29:09 UTC ---
Author: jason
Date: Fri Nov 11 04:29:04 2011
New Revision: 181280

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181280
Log:
    PR c++/50372
    * pt.c (convert_nontype_argument_function): Allow decls with
    internal linkage in C++11.
    (convert_nontype_argument): Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/template/linkage1.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/ext/visibility/anon8.C
    trunk/gcc/testsuite/g++.dg/parse/template21.C
    trunk/gcc/testsuite/g++.old-deja/g++.other/linkage4.C

[Bug c++/50372] [C++0x] pointers to static functions should be valid template parameters

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50372

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |jason at gcc dot gnu.org
         Resolution|                            |FIXED
   Target Milestone|---                         |4.7.0

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-13 05:54:16 UTC ---
Fixed for 4.7.