On Wed, Apr 15, 2009 at 4:16 PM, Dominique Devienne <ddevienne@gmail.com> wrote:
From my very limited meta-programming experience, I'm guessing I need to fix the current typedef shared_ptr<ident_type> ident_ptr; in ObjectPtr to somehow use MPL to "return" shared_ptr<typename T::ident_type const> given a const T, and shared_ptr<typename T::ident_type> given a T, but I don't know how to do that yet.
If someone would be kind enough to point me in the right direction, I'd appreciate. Thanks, --DD
I figured the following which seems to work fine. Didn't think I could do it on my own in 15min, thus my post ;) --DD #include <boost/type_traits/is_const.hpp> #include <boost/type_traits/remove_const.hpp> #include <boost/mpl/if.hpp> template <class T> class ObjectPtr { public: typedef typename remove_const<T>::type object_type; typedef typename object_type::ident_type ident_type; typedef shared_ptr< typename mpl::if_c<is_const<T>::value, ident_type const, ident_type>::type > ident_ptr; public: ident_ptr ident() const { return ident_; } private: ident_ptr ident_; };