Hi All, I've made a simple implementation of making a class non-derivable. Aside from the pros/cons of actually using this, which I'm sure could be debated for months, I thought I'd present the implementation anyway to see if there is interest in it. I thought something like this might already be in Boost, but I couldn't locate it, or any threads about the subject. Usage is as: class Foo : Sealed<Foo> {}; class Bar : Foo {}; // Error. And it should all work as intended (unless I've missed something) and not allow you to instantiate Bar. --- Implementation --- namespace Detail { template <class T, class Parent> class Sealed { friend T; friend Parent; }; } template <class T> class Sealed : public virtual Detail::Sealed<T, Sealed> { friend T; }; --- kalin