diff --git a/include/boost/detail/shared_count.hpp b/include/boost/detail/shared_count.hpp
index 8756294..cf97746 100644
--- a/include/boost/detail/shared_count.hpp
+++ b/include/boost/detail/shared_count.hpp
@@ -25,6 +25,8 @@
 #include <boost/checked_delete.hpp>
 #include <boost/detail/atomic_count.hpp>
 
+#include <functional>         // for std::less
+
 namespace boost
 {
 
@@ -215,6 +217,16 @@ public:
     {
         return pi_->use_count() == 1;
     }
+
+    friend inline bool operator==(shared_count const & a, shared_count const & b)
+    {
+        return a.pi_ == b.pi_;
+    }
+
+    friend inline bool operator<(shared_count const & a, shared_count const & b)
+    {
+        return std::less<counted_base *>()(a.pi_, b.pi_);
+    }
 };
 
 class weak_count
@@ -275,6 +287,16 @@ public:
     {
         return pi_->use_count();
     }
+
+    friend inline bool operator==(weak_count const & a, weak_count const & b)
+    {
+        return a.pi_ == b.pi_;
+    }
+
+    friend inline bool operator<(weak_count const & a, weak_count const & b)
+    {
+        return std::less<counted_base *>()(a.pi_, b.pi_);
+    }
 };
 
 } // namespace detail
diff --git a/include/boost/shared_ptr.hpp b/include/boost/shared_ptr.hpp
index c13c3a8..76ecdbb 100644
--- a/include/boost/shared_ptr.hpp
+++ b/include/boost/shared_ptr.hpp
@@ -29,6 +29,7 @@
 #include <memory>             // for std::auto_ptr
 #include <algorithm>          // for std::swap
 #include <functional>         // for std::less
+#include <typeinfo>           // for std::bad_cast
 
 #ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash
 # pragma warning(push)
diff --git a/include/boost/weak_ptr.hpp b/include/boost/weak_ptr.hpp
index 170359d..2b7120e 100644
--- a/include/boost/weak_ptr.hpp
+++ b/include/boost/weak_ptr.hpp
@@ -22,7 +22,7 @@
 #include <boost/detail/shared_count.hpp>
 
 #include <algorithm>          // for std::swap
-#include <functional>         // for std::less
+#include <typeinfo>           // for std::bad_cast
 
 #ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash
 # pragma warning(push)
@@ -133,6 +133,11 @@ public:
         pn.swap(other.pn);
     }
 
+    bool less(this_type const & rhs) const // implementation detail, never throws
+    {
+        return pn < rhs.pn;
+    }
+
 // Tasteless as this may seem, making all members public allows member templates
 // to work in the absence of member template friends. (Matthew Langston)
 
@@ -161,7 +166,7 @@ template<class T, class U> inline bool operator!=(weak_ptr<T> const & a, weak_pt
 
 template<class T> inline bool operator<(weak_ptr<T> const & a, weak_ptr<T> const & b)
 {
-    return std::less<T*>()(a.get(), b.get());
+    return a.less(b);
 }
 
 template<class T> void swap(weak_ptr<T> & a, weak_ptr<T> & b)
diff --git a/shared_ptr_test.cpp b/shared_ptr_test.cpp
index 7387cc8..dc1282a 100644
--- a/shared_ptr_test.cpp
+++ b/shared_ptr_test.cpp
@@ -46,6 +46,11 @@ struct X
         std::cout << "X(" << this << ")::~X()\n";
     }
 
+    virtual int id() const
+    {
+        return 1;
+    }
+
 private:
 
     X(X const &);
@@ -66,6 +71,11 @@ struct Y: public X
         std::cout << "Y(" << this << ")::~Y()\n";
     }
 
+    virtual int id() const
+    {
+        return 2;
+    }
+
 private:
 
     Y(Y const &);
@@ -86,6 +96,76 @@ void release_object(int * p)
     std::cout << "release_object()\n";
 }
 
+template<class T> void test_is_X(T const & p)
+{
+    BOOST_TEST(p->id() == 1);
+    BOOST_TEST((*p).id() == 1);
+}
+
+template<class T> void test_is_Y(T const & p)
+{
+    BOOST_TEST(p->id() == 2);
+    BOOST_TEST((*p).id() == 2);
+}
+
+// std::rel_ops::operator!= breaks x != y when defined in the global namespace
+
+#if defined(__STL_BEGIN_RELOPS_NAMESPACE) && !defined(__STL_USE_NAMESPACE_FOR_RELOPS)
+#  define BOOST_BROKEN_INEQUALITY
+#endif
+
+template<class T> void test_eq(T const & a, T const & b)
+{
+    BOOST_TEST(a == b);
+
+#ifndef BOOST_BROKEN_INEQUALITY
+
+    BOOST_TEST(!(a != b));
+
+#endif
+
+    BOOST_TEST(!(a < b));
+    BOOST_TEST(!(b < a));
+}
+
+template<class T> void test_ne(T const & a, T const & b)
+{
+    BOOST_TEST(!(a == b));
+
+#ifndef BOOST_BROKEN_INEQUALITY
+
+    BOOST_TEST(a != b);
+
+#endif
+
+    BOOST_TEST(a < b || b < a);
+    BOOST_TEST(!(a < b && b < a));
+}
+
+template<class T, class U> void test_eq2(T const & a, U const & b)
+{
+    BOOST_TEST(a == b);
+
+#ifndef BOOST_BROKEN_INEQUALITY
+
+    BOOST_TEST(!(a != b));
+
+#endif
+
+}
+
+template<class T, class U> void test_ne2(T const & a, U const & b)
+{
+    BOOST_TEST(!(a == b));
+
+#ifndef BOOST_BROKEN_INEQUALITY
+
+    BOOST_TEST(a != b);
+
+#endif
+
+}
+
 int test_main(int, char * [])
 {
     using namespace boost;
@@ -94,6 +174,15 @@ int test_main(int, char * [])
         shared_ptr<X> p(new Y);
         shared_ptr<X> p2(new X);
 
+        test_is_Y(p);
+        test_is_X(p2);
+        test_ne(p, p2);
+
+        {
+            shared_ptr<X> q(p);
+            test_eq(p, q);
+        }
+
         shared_ptr<Y> p3 = shared_dynamic_cast<Y>(p);
         shared_ptr<Y> p4 = shared_dynamic_cast<Y>(p2);
 
@@ -102,8 +191,14 @@ int test_main(int, char * [])
         BOOST_TEST(p3.use_count() == 2);
         BOOST_TEST(p4.use_count() == 1);
 
+        test_is_Y(p3);
+        test_eq2(p, p3);
+        test_ne2(p2, p4);
+
         shared_ptr<void> p5(p);
 
+        test_eq2(p, p5);
+
         std::cout << "--\n";
 
         p.reset();
@@ -125,14 +220,20 @@ int test_main(int, char * [])
         BOOST_TEST(wp2.use_count() == 1);
         BOOST_TEST(wp2.get() != 0);
 
+        test_is_Y(wp2);
+        test_ne(wp1, wp2);
+
         weak_ptr<Y> wp3 = shared_dynamic_cast<Y>(wp2);
 
         BOOST_TEST(wp3.use_count() == 1);
         BOOST_TEST(wp3.get() != 0);
-        BOOST_TEST(wp2 == wp3);
+
+        test_eq2(wp2, wp3);
 
         weak_ptr<X> wp4(wp3);
 
+        test_eq(wp2, wp4);
+
         wp1 = p2;
         wp1 = p4;
         wp1 = wp3;
@@ -140,7 +241,13 @@ int test_main(int, char * [])
 
         BOOST_TEST(wp1.use_count() == 1);
         BOOST_TEST(wp1.get() != 0);
-        BOOST_TEST(wp1 == wp2);
+
+        test_eq(wp1, wp2);
+
+        weak_ptr<X> wp5;
+
+        bool b1 = wp1 < wp5;
+        bool b2 = wp5 < wp1;
 
         p5.reset();
 
@@ -153,6 +260,12 @@ int test_main(int, char * [])
         BOOST_TEST(wp3.use_count() == 0);
         BOOST_TEST(wp3.get() == 0);
 
+        // Test operator< stability for std::set< weak_ptr<> >
+        // Thanks to Joe Gottman for pointing this out
+
+        BOOST_TEST(b1 == (wp1 < wp5));
+        BOOST_TEST(b2 == (wp5 < wp1));
+
         shared_ptr<int> p6(get_object(), release_object);
     }