I've uploaded a new lib 'yield_iterator' (http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost.yield_iterator-0.1.0.zip&directory=Iterators&). Documentation can be found also here: http://ok73.ok.funpic.de/boost/libs/yield_iterator/docu/html/ . The lib provides the same functionality as C# does with the 'yield return' and 'yield break' statements - this lib provides an easy way to iterate complex containers. The library uses boost.context internally. For instance iterating an tree would usally require to traverse the complete tree and store the nodes in a STL container - the begin/end iterators of this STL container are used to iterate the tree. With boost.yield_iterator you have only to derive a class from yield_adapter and overload the function 'void iterate()'. In 'void iterate()' you can iterate locally over the internal data and return appropriate elements via 'yield_return()'. class tree_adapter : public boost::yield_adapter< leaf >, public visitor { private: node::ptr_t root_; public: tree_adapter() : boost::yield_adapter< leaf >(), root_() {} tree_adapter( node::ptr_t root) : boost::yield_adapter< leaf >( true), root_( root) { BOOST_ASSERT( root_); } void visit( branch & b) { if ( b.left) b.left->accept( * this); if ( b.right) b.right->accept( * this); } void visit( leaf & l) { yield_return( l); } void iterate() { root_->accept( * this); } }; int main( int argc, char * argv[]) { { node::ptr_t root = create_tree(); boost::yield_iterator< tree_adapter > e; for ( boost::yield_iterator< tree_adapter > i( root); i != e; ++i) { std::cout << i->value << ""; } } std::cout << "\nDone" << std::endl; return EXIT_SUCCESS; } The library contains a example iterating over a tree via visitor pattern an yield_iterator. I hope I get some feedback. best regards, Oliver