Is this a bug of gcc ?

[Pierre Chatelier]

Hello,

I cannot compile a code that seems correct to me. I have tried with  
gcc 3.3 and gcc 4.0.1 on MacOS X-ppc, and gcc 4.0.1 on Linux i686.

Here is the code, that uses pure virtual functions and simple  
inheritance.

//-------------------------------------
struct a
{
  virtual int foo() =0;
  virtual ~a(){}
};

struct b : public a
{
  virtual int foo(int a) =0;
  virtual ~b(){}
};

struct c : public b
{
  int test()
   {
     return (foo() + // <--- the compiler claims here that it cannot  
find foo()
             foo(2));
  }
  virtual ~c(){}
};

struct d : public c
{
  virtual int foo() {return 1;}
  virtual int foo(int a) {return a;}
  virtual ~d(){}
};

int main()
{
  d call;
  return call.test();
}
//-------------------------------------

The compiler claims that it cannot find foo. I have found two  
possible workarounds :
	-repeat the "virtual int foo() =0;" prototype in the declaration of  
struct b
or
        -change the foo(void) function into a bar(void) function.

I am under the impression that it is a bug of gcc. Should I fill a  
bug, or am I the one who is confused ?

Pierre Chatelier