"Peter Dimov" <pdimov@mmltd.net> wrote in message news:011801c54c25$f9f3c2d0$6401a8c0@pdimov2... | Howard Hinnant wrote: | > I've got 3 ownership policies on my mind: | > | > 1. shared | > 2. unique | > 3. cloned | > | > And if anything I'm leaning towards shallow const on all of them. | > However I also believe deep const versions of all of these would | > probably be valuable as well. And I'm especially looking at | > signatures like: | > | > template<class T, class U> | > bool operator==(const shared_ptr<T>& a, const shared_ptr<U>& b); | > | > shared_ptr today is a shallow const animal, and I think that is good. | > But the above signature assumes deep const. It would be nice to have | > a zero-overhead way to express and enforce that assumption. | | I'm not sure I understand. Why does the above assume deep const? It's just | the shared_ptr equivalent of: | | template<class T, class U> | bool operator==(T * const & a, U * const & b); it's unreasable to requrie the state of T and U to be avaiable through non-const member functions. -Thorsten