[Bug c++/53624] New: GCC rejects function local types in template function with default template arguments

[Bug c++/53624] New: GCC rejects function local types in template function with default template arguments

[lunow at math dot hu-berlin.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

             Bug #: 53624
           Summary: GCC rejects function local types in template function
                    with default template arguments
    Classification: Unclassified
           Product: gcc
           Version: 4.6.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: lunow@math.hu-berlin.de


Created attachment 27595
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27595
testcase

The error occurs when there is at one template argument with default and one
without. Errors are generated for local structs, classes, unions and lambda
functions.
For the attached usecase I get with gcc 4.6.3 and 4.7.0:
C:\dev\projects\compiler test>g++ gcc_test2.cpp --std=c++0x -fsyntax-only
gcc_test2.cpp: In function 'void Foo(T)':
gcc_test2.cpp:5:12: error: no default argument for 'T'

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-06-10 04:24:44 UTC ---
>gcc_test2.cpp:5:12: error: no default argument for 'T'

It is not rejecting the local type but rather it is rejecting the second
template argument which does not have a default argument even though the first
argument does.

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[lunow at math dot hu-berlin.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

--- Comment #2 from Daniel Lunow <lunow at math dot hu-berlin.de> 2012-06-10 04:49:29 UTC ---
Their is no requirement (in the c++11 standard) for function templates that
implies subsequent template parameters after a template parameter with default
template argument must also have default template arguments (in contrast to
class templates). In general this works in gcc.
But with the local types inside the template function gcc might reject it
because it creates local types as templated with the same template
parameters/default arguments and checks the requirement for class templates.

The line number/offset in the error message clearly refers to the local struct.

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-06-10 04:52:21 UTC ---
Oh I see.
The trunk shows what is going on better:
t.cc: In function ‘void Foo(T)’:
t.cc:4:12: error: no default argument for ‘T’
   struct X {};
            ^

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |likan_999.student at sina
                   |                            |dot com

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-28 13:17:35 UTC ---
*** Bug 54104 has been marked as a duplicate of this bug. ***

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-07-28
         AssignedTo|unassigned at gcc dot       |paolo.carlini at oracle dot
                   |gnu.org                     |com
   Target Milestone|---                         |4.8.0
     Ever Confirmed|0                           |1

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-28 13:20:08 UTC ---
Looking into it.

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[paolo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

--- Comment #6 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2012-07-31 09:46:59 UTC ---
Author: paolo
Date: Tue Jul 31 09:46:46 2012
New Revision: 190001

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190001
Log:
/cp
2012-07-31  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/53624
    * pt.c (check_default_tmpl_args): Don't check local types.

/testsuite
2012-07-31  Paolo Carlini  <paolo.carlini@oracle.com>

    PR c++/53624
    * g++.dg/cpp0x/temp_default5.C: New.


Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/temp_default5.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/pt.c
    trunk/gcc/testsuite/ChangeLog

[Bug c++/53624] GCC rejects function local types in template function with default template arguments

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53624

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

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

--- Comment #7 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-07-31 09:49:41 UTC ---
Fixed.