Re: c++/10514: incorrect parsing of template instatiation with pointer-to-member variables

Re: c++/10514: incorrect parsing of template instatiation with pointer-to-member variables

[giovannibajo]

Synopsis: incorrect parsing of template instatiation with pointer-to-member variables

State-Changed-From-To: analyzed->closed
State-Changed-By: bajo
State-Changed-When: Fri May 16 01:22:17 2003
State-Changed-Why:
    Duplicate of c++/8222. The code is known to be legal, but
    it is currently rejected by GCC up to current mainline.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10514

Re: c++/10514: incorrect parsing of template instatiation with pointer-to-member variables

[reichelt]

Synopsis: incorrect parsing of template instatiation with pointer-to-member variables

State-Changed-From-To: open->analyzed
State-Changed-By: reichelt
State-Changed-When: Mon Apr 28 13:56:14 2003
State-Changed-Why:
    Confirmed.
    The parser hickups affect all release versions since 2.95.x,
    as well as 3.3 branch and mainline.
    
    BTW, not only using
      i_1->A::TFUNC_A<w_a,w_b>( m_b1 );
    but also writing
      i_1->template TFUNC_A<w_a,w_b>( m_b1 );
    makes the code compile.
    
    The problem can also be demonstrated with the following code snippet:
    
    ============================snip here===============================
    struct A
    {
        template <int> void foo() {}
    };
    
    struct B
    {
        template <int> void bar (A* p)
        {
            p->foo<0>(); // compiler trouble
        }
    
        void baz (A* p)
        {
            bar<0>(p);
        }
    };
    ============================snip here===============================
    
    Regards,
    Volker

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10514

c++/10514: incorrect parsing of template instatiation with pointer-to-member variables

[gianni]

>Number:         10514
>Category:       c++
>Synopsis:       incorrect parsing of template instatiation with pointer-to-member variables
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Apr 27 15:36:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     gianni@mariani.ws
>Release:        gcc 3.2.1
>Organization:
>Environment:
Linux X86 RH 7.2
>Description:

The lines in question (see listing below) are:

           i_1->A::TFUNC_A<w_a,w_b>( m_b1 );

           i_1->TFUNC_A<w_a,w_b>( m_b1 ); // compiler trubbell

without the A:: it seems like it fails to parse.

side notes:
  Apparently MSVC++ 7.0 and Borland compiles it fine 
  confirmed by Rob Williscroft on news:comp.lang.c++
  MSVC++ 6.0sp5 dumps an internal compiler error.

On the code below GCC 3.2.1 gives the following message:
g++     tt2.cpp   -o tt2
tt2.cpp: In member function `void Zoo::B::TFUNC_B(Zoo::A*) [with
  Zoo::A*Zoo::A::*w_a = &Zoo::A::m_mem1, Zoo::A*Zoo::B::*w_b =
  &Zoo::B::m_b1]':
tt2.cpp:68:   instantiated from here
tt2.cpp:54: invalid use of member (did you forget the `&' ?)
tt2.cpp:54: comparison between distinct pointer types `Zoo::A*Zoo::B::*' and `
  Zoo::A*' lacks a cast
make: *** [tt2] Error 1



class Zoo
{

public:

   class B;
     class A
   {

       public:


       A           * m_mem1;
       A           * m_mem2;

       template <
           A * A::*    w_a,
           A * B::*    w_b
       >
       void TFUNC_A( A * i_1 )
       {
           i_1->*w_a = i_1;
       }

       typedef void ( A::* F_TA )( A * i_1 );

         };

   class B
   {

       public:

       A           * m_b1;
       A           * m_b2;

       typedef void ( B::* F_TB )( A * i_1 );

       template <
           A * A::*    w_a,
           A * B::*    w_b
       >
       void TFUNC_B( A * i_1 )
       {
           static const A::F_TA gg = ( & A::TFUNC_A<w_a,w_b> );
                 ( i_1->*gg )( m_b1 );

           i_1->A::TFUNC_A<w_a,w_b>( m_b1 );
           i_1->TFUNC_A<w_a,w_b>( m_b1 ); // compiler trubbel
       }

       void Fooey( A * i_1 )
       {
//          static A * A::* const l_mem1 = &A::m_mem1;
//          static A * B::* const l_b1 = &B::m_b1;
//          this->TFUNC_B< l_mem1, l_b1 >( i_1 );
          //          static const F_TB gg = &B::TFUNC_B< l_mem1, l_b1 >;

//            static const F_TB gg = &B::TFUNC_B< (&A::m_mem1), (&B::m_b1) >;
//            (this->*gg)( i_1 );
                      this->TFUNC_B< &A::m_mem1, &B::m_b1 >( i_1 );
       }
         };


};


int main()
{
   Zoo::A      a[1];
   Zoo::B      b[1];

   b->Fooey( a );

   return 0;
}
>How-To-Repeat:
compile code in description
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: