diff --exclude='*~' --exclude='.*' -I '$Id:' -urN dvenv-0.2.2.orig/dvenv/env.h dvenv-0.2.2/dvenv/env.h
--- dvenv-0.2.2.orig/dvenv/env.h	2005-05-12 23:43:00.000000000 -0400
+++ dvenv-0.2.2/dvenv/env.h	2005-05-12 23:47:34.000000000 -0400
@@ -596,6 +596,7 @@
     class iterator {
     public:
       typedef std::map<std::string,const Env*>::iterator::value_type value_type;
+      virtual ~iterator() { }
       virtual iterator& operator++();
       virtual value_type operator*() const;
       virtual bool equal(const iterator* i) const;
@@ -721,6 +722,7 @@
     class iterator: public Box::iterator {
     public:
       iterator(Map::const_iterator it): it_(it) {}
+      virtual ~iterator() { }
       iterator& operator++() { ++it_; return *this; }
       value_type operator*() const { return *it_; }
       bool equal(const Box::iterator* i) const;
@@ -763,6 +765,7 @@
     class iterator: public Box::iterator {
     public:
       iterator(Vector::const_iterator it, const Vector* v);
+      virtual ~iterator() { }
       iterator& operator++() { ++it_; return *this; }
       value_type operator*() const;
       bool equal(const Box::iterator* i) const;