I think you have to say something about the copy semantics too, because if you ignore those, value_ptr would be synonymous with unique_ptr. class Tree { Tre

I think you have to say something about the copy semantics too, because if you ignore those, value_ptr would be synonymous with unique_ptr. class Tree { Tree *_left, *_right; }; Tree y = x; makes a shallow copy. class Tree { unique_ptr<Tree> _left, _right; }; Tree y = x; doesn't compile, but class Tree { value_ptr<Tree> _left, _right; }; Tree y = x; makes a deep copy.