+// Provide global definitions of external inverse depth first iterators...
+template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> >
+struct idf_ext_iterator : public idf_iterator<T, SetTy, true> {
+ idf_ext_iterator(const idf_iterator<T, SetTy, true> &V)
+ : idf_iterator<T, SetTy, true>(V) {}
+ idf_ext_iterator(const df_iterator<Inverse<T>, SetTy, true> &V)
+ : idf_iterator<T, SetTy, true>(V) {}
+};
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_begin(const T& G, SetTy &S) {
+ return idf_ext_iterator<T, SetTy>::begin(Inverse<T>(G), S);
+}
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_end(const T& G, SetTy &S) {
+ return idf_ext_iterator<T, SetTy>::end(Inverse<T>(G), S);
+}
+
+template <class T, class SetTy>
+iterator_range<idf_ext_iterator<T, SetTy>> inverse_depth_first_ext(const T& G,
+ SetTy &S) {
+ return make_range(idf_ext_begin(G, S), idf_ext_end(G, S));
+}
+
+} // End llvm namespace
+