[Boost-users] [lambda] typeid & abstract base class

From: Roman Krylov (Roman.Krylov_at_[hidden])
Date: 2006-02-17 09:09:42

Hi all.
I want to make function comparing two typeid's 'const T&'s , but in 
context I have only two T* pointers.
T is abstract class having pure virtual functions.
typeid operator takes reference, not pointer.
If I use * operator on placeholder (ll_typeid(*_1)==ll_typeid(*_2)) - 
compiler complains that it could not instantiate T somewhere in some 
complex template.
I also tried to use ll_static_cast in expression, but it didn't help.
I don't attach those error messages, but anyway why should T be 
instantiated to construct L-expression with *(T*)?
By the way I made simple functor and it works the way I want, but it's 6 
lines long instead of one in_place expr. :
>     template<typename T>
>     struct compareRefsByTypeID
>     {
>     bool operator()(const T* t1, const T* t2)
>         { return typeid((const T&)(*t1))==typeid((const T&)(*t2)); }
>     };
regards,
    Roman.