http://boost.org/libs/smart_ptr/intrusive_ptr.html says: "As a general rule, if it isn't obvious whether intrusive_ptr better fits your needs than shared_ptr, try a shared_ptr-based design first." I wonder why? Embedding the refcounter into the object seems to me much more natural and performant than adding another free-store allocation which shared_ptr requires. Another related thing is why is there no complementary class to add a refcounter to an object? Something like template<typename ObjectType> struct refcount { refcount(): refs(0) {} ~refcount(){} private: refcount( refcount const&); refcount& operator=(refcount const&); friend void intrusive_ptr_add_ref( ObjectType* o) { static_cast<refcount<ObjectType>*>(o)->add_ref(); } void add_ref() { inc(refs); } friend void intrusive_ptr_release( ObjectType* o) { static_cast<refcount<ObjectType>*>(o)->release(); } void release() { dec(refs); if(!refs) delete static_cast<ObjectType*>(this); } some-integer-type refs; }; (I think that I can't legally inject functions into the surrounding namespace via these friend functions, but maybe there's a workaround and this is just a sketch. ) Uli