[boost] [pointer container] Wishlist: Iterating through nullable vectors and compiler firewalls

Two quick queries. Would it make sense to have the iterator increment and decrement operators and begin() member function of ptr_vector< nullable<> > skip missing records so that applications have no need to check? What is stopping pointer container classes from being used with opaque types as a compilation firewall? -- Andrew Hain Oasys http://www.oasys-software.com