Re: Two-stage name lookup problem

[Jakub Pawlewicz <jakub dot pawlewicz at gmail dot com>]

I found a workaround. It looks ugly, but it works. I used dummy
template arguments to overcome instantiation. I hope somebody will
find a nicer solution. Here is a hacked code:

template <typename Dummy> struct A_impl;

typedef A_impl<void> A;

template <typename Dummy>
struct A_impl {
 int x;
 A_impl(int x) : x(x) { }

  template <int X, typename Dummy2>
  struct B {
    A_impl<Dummy2> a;
    B() : a(X) { }
    void f() { }
  };

  template <int X>
   void f()
   {
     B<X, Dummy> b;
     b.f();
   }
};

int main()
{
  A a(0);
  a.f<0>();
}


2005/10/26, Jakub Pawlewicz <jakub.pawlewicz@gmail.com>:
> I have problem with templates and I need a solution. I want to use
> inner class B with a member of outer class A type. Then I wand class A
> to use template class B in function f. Here is code I want to change
> in order to compile with gcc 3.4. It compiles fine with gcc 3.3.
>
> struct A {
>  int x;
>  A(int x) : x(x) { }
>
>  template <int X>
>  struct B {
>    A a;
>    B() : a(X) { }
>    void f() { }
>  };
>
>  template <int X>
>  void f()
>  {
>    B<X> b;
>    b.f();
>  }
> };
>
> int main()
> {
>  A a(0);
>  a.f<0>();
> }
>
> Compilation fails with a message
> a.cpp:7: error: field `a' has incomplete type
> a.cpp: In constructor `A::B<X>::B()':
> a.cpp:8: error: class `A::B<X>' does not have any field named `a'
>
> Is there any workaround?
>
> Thanks in advance
>
> Jakub Pawlewicz
>