On Sun, Feb 12, 2012 at 9:25 AM, Patrick LeBoutillier
<[email protected]> wrote:
> I'm really no C++ expert, but I think the implementation is not viable
> the way it is. If you create a
> small C++ program that simulates Inline::CPP like this:
>
> #include <stdio.h>
>
> /* Your Child/Parent classes here "as is" */
>
> int main(int argv, char **argc){
> Child *c = new Child() ;
> printf("%d\n", c->do_something()) ;
> printf("%d\n", c->do_another()) ;
>
> void *x = c ;
> printf("%d\n", ((Parent1 *)x)->do_something()) ;
> printf("%d\n", ((Parent2 *)x)->do_another()) ;
> }
>
> I gives the same error:
> 51
> 17
> 51
> 51
>
Patrick,
Your explanation was excellent.
What needs to be happening is that, as Child inherits from Parent1 and
Parent2, the pointer should be cast as a Child type, like in this
modification of your test:
int main(int argv, char **argc){
Child *c = new Child() ;
printf("%d\n", c->do_something()) ;
printf("%d\n", c->do_another()) ;
void *x = c ;
printf("%d\n", ((Child *)x)->do_something()) ;
printf("%d\n", ((Child *)x)->do_another()) ;
}
...or in more idiomatic C++:
int main() {
using std::cout;
using std::endl;
Child *c = new Child() ;
cout << c->do_something() << endl;
cout << c->do_another() << endl;
void *x = c ;
cout << static_cast< Child* >(x)->do_something() << endl;
cout << static_cast< Child* >(x)->do_another() << endl;
return 0;
}
Though I'm not much closer to a solution, at least your message
reminded me that we're dealing with void pointers to objects. Maybe I
need to start looking at how and where the casting is being
accomplished.
Dave
--
David Oswald
[email protected]
