Re: Two-stage name lookup problem

[corey taylor <corey dot taylor at gmail dot com>]

Jakub,

  The declaration of A a; in struct B because it requires an object
size.  Using a pointer to an incomplete type is allowed.  You could
create a new A in the B constructor and assign it to a pointer.

  The other errors center around this.  The question about using B b
has nothing to do with the error above.

Corey

On 10/26/05, Jakub Pawlewicz <jakub.pawlewicz@gmail.com> wrote:
> > Your problem is not with templates.
> >
> > Here's your problem in a nutshell...
> >
> > struct A
> > {
> >     int x;
> >
> >     struct B
> >     {
> >         A a;
> >     };
> > };
> >
> >
> > You cannot use A within B, because at that point A is incomplete.
> >
> > You can pull B out of A.  If you want B to be in the A namespace, change
> > 'struct A' to 'namespace A', and make 'struct A_impl', fully declared, and
> > then use that within 'struct B'.
>
> But what about function f(), the member of struct A? I want to declare
> variable with type B in the body of the function:
>
> struct A {
>     ...
>     void f()
>     {
>         B b;
>         ...
>     }
> };
>
> I am aware that kind of code may be ill formed, but when using
> templates, there should be something like deferred instantiation.
> Struct B is a template and also function A::f() is a template. Struct
> B is needed only when function A::f() is used. Struct B should be able
> to construct member of type A and Struct B do not use function A::f().
> I want all functions be inline. Any solutions?
>