[Bug c++/48647] New: [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[Bug c++/48647] New: [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[gintensubaru at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

           Summary: [C++0x] SFINAE does not handle incompatible pointer
                    types well in conditional operator
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: gintensubaru@gmail.com


template< class T >
T&& declval();

template< class T, class U >
decltype( true ? declval<T>() : declval<U>() ) test( int );

template< class T, class U >
void test( ... );


template< class T, class U >
struct is_same {
  static const bool value = false;
};

template< class T >
struct is_same<T, T> {
  static const bool value = true;
};

int main()
{
  typedef decltype( test<int*, double*>(0) ) void_expected;
  static_assert( is_same<void_expected, void>::value,  "This should be true,
and" );
  static_assert( is_same<void_expected, void*>::value, "this should be false."
);
}

-------------------


In this code, type of expression 'test<int*, double*>(0)' should be void,
but gcc (-std=c++0x) says it's void*, on all of following versions:

4.5.1
4.6.0
4.6.1-20110415
4.7.0-20110416

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

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

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

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-04-17 21:49:18 UTC ---
Likewise...

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.05.22 18:57:58
         AssignedTo|unassigned at gcc dot       |jason at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-22 18:59:30 UTC ---
*** Bug 48646 has been marked as a duplicate of this bug. ***

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

--- Comment #2 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-22 18:48:42 UTC ---
Author: jason
Date: Sun May 22 18:48:39 2011
New Revision: 174031

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174031
Log:
    PR c++/48647
    * typeck.c (composite_pointer_type_r): Return error_mark_node
    on error in SFINAE context.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/sfinae23.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/typeck.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/g++.dg/template/sfinae8.C

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-22 20:32:03 UTC ---
Author: jason
Date: Sun May 22 20:31:59 2011
New Revision: 174044

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174044
Log:
    PR c++/48647
    * typeck.c (composite_pointer_type_r): Return error_mark_node
    on error in SFINAE context.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/g++.dg/cpp0x/sfinae23.C
Modified:
    branches/gcc-4_6-branch/gcc/cp/ChangeLog
    branches/gcc-4_6-branch/gcc/cp/typeck.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_6-branch/gcc/testsuite/g++.dg/template/sfinae8.C

[Bug c++/48647] [C++0x] SFINAE does not handle incompatible pointer types well in conditional operator

[jason at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48647

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.6.1

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> 2011-05-25 01:19:50 UTC ---
Fixed for 4.6.1.