In file included from /home/tommie/Programming/ultimatepp/bazaar/TreeTest/main.cpp:1: In file included from /home/tommie/Programming/ultimatepp/bazaar/TreeTest/TreeTest.h:11: /home/tommie/Programming/ultimatepp/bazaar/Tree/Tree.h:112:11: error: dependent using declaration resolved to type without 'typename' using B::ConstIterator; ^ /home/tommie/Programming/ultimatepp/bazaar/Tree/Tree.h:152:11: note: in instantiation of template class 'Upp::Tree<Upp::Node<Upp::One<Element> > >' requested here : public Tree<Node<T> > ^ /home/tommie/Programming/ultimatepp/bazaar/TreeTest/TreeTest.h:31:22: note: in instantiation of template class 'Upp::Node<Upp::One<Element> >' requested here Node<One<Element> > root; ^ /home/tommie/Programming/ultimatepp/uppsrc/Core/Vcont.h:449:8: note: target of using declaration class ConstIterator { ^