Re: Overload lookup of pointer-to-member

From:
Abhishek Padmanabh <abhishek.padmanabh@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Sat, 12 Jul 2008 00:49:38 -0700 (PDT)
Message-ID:
<0f4734e5-d4ee-4f48-a46e-3302af545067@c65g2000hsa.googlegroups.com>
On Jul 12, 8:14 am, "jkn...@gmail.com" <jkn...@gmail.com> wrote:

In the following program, if the call to bar does not specify the type
as <int>, gcc gives the error "no matching function for call to
=91bar(A&, <unresolved overloaded function type>)'". Since bar
explicitly takes a pointer-to-member with no parameters, why is the
lookup for the overloaded function not able to use the number of
arguments to determine the appropriate function? Is there a relevant
portion of the standard that governs the lookup rules in this case?

Thanks in advance,
Jeff

#include <iostream>
using namespace std;

class A
{
        public:
        int foo()
        {
                cout << "int foo" << endl;
                return 5;
        }
        template <class A>
        void foo (A a)
        {
                cout << "template foo" << endl;
        }

};

template <class Type, class Obj>
void bar (Obj& obj, Type (Obj::*func)())
{
        Type t = (obj.*func)();
        cout << "TYPE: " << t << endl;}

int main ()
{
        A a;
        bar<int>(a, &A::foo); //<int> required, even though only one of t=

he

functions takes no arguments
        bar(a, &A::foo); //doesn't compile
}


Compiles fine with Comeau online and VC++ 2005. So, could be there's
something wrong with g++ (an older version, may be).

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