C++ Parser problem or I need glasses - template pointer to member parameters

C++ Parser problem or I need glasses - template pointer to member parameters

[Gianni Mariani]

The lines in question 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.

Time for a bug report ? 

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;
}

Re: C++ Parser problem or I need glasses - template pointer to member parameters

[Nathan Sidwell]

Gianni Mariani wrote:
> 
> The lines in question are:
> 
>            i_1->A::TFUNC_A<w_a,w_b>( m_b1 );
> 
>            i_1->TFUNC_A<w_a,w_b>( m_b1 ); // compiler trubbell
I think this is a bug. we don't properly find TFUNC_A during the definition of
TFUNC_B. please file a bug report.

BTW
	i_1->template TFUNC_A<....> works too

nathan


-- 
Nathan Sidwell    ::   http://www.codesourcery.com   ::     CodeSourcery LLC
          The voices in my head said this was stupid too
nathan@codesourcery.com : http://www.cs.bris.ac.uk/~nathan/ : nathan@acm.org