I wonder if this is correct:

#include <typeinfo.h>

struct A
{
 A(const type_info& i = typeid(A)) : info(i) { }
 const type_info& info;
};

Note the usage of "typeid(A)" as a default argument.
My compiler complains: "illegal use of incomplete struct: A"
I do not see any reason why using A should be forbidden in default
argument initializations...

So, is the above syntax correct, or is my compiler right?

Thanks,

 Gabor



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Gabor Greif wrote:
>
> I wonder if this is correct:
>
> #include <typeinfo.h>
>
> struct A
> {
>         A(const type_info& i = typeid(A)) : info(i) { }
>         const type_info&        info;
> };
>
> Note the usage of "typeid(A)" as a default argument.
> My compiler complains: "illegal use of incomplete struct: A"
> I do not see any reason why using A should be forbidden in default
> argument initializations...
>
> So, is the above syntax correct, or is my compiler right?

Yes, your compiler is right. typeid(A) requires a complete type, and A
isn't complete yet at that point.


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