+/**
+ * Support for boost::mem_fn
+ */
+template<typename T>
+T* get_pointer(SGSharedPtr<T> const & p)
+{
+ return p.ptr();
+}
+
+/**
+ * static_cast for SGSharedPtr
+ */
+template<class T, class U>
+SGSharedPtr<T> static_pointer_cast(SGSharedPtr<U> const & r)
+{
+ return SGSharedPtr<T>( static_cast<T*>(r.get()) );
+}
+
+/**
+ * Compare two SGSharedPtr<T> objects for equality.
+ *
+ * @note Only pointer values are compared, not the actual objects they are
+ * pointing at.
+ */
+template<class T, class U>
+bool operator==(const SGSharedPtr<T>& lhs, const SGSharedPtr<U>& rhs)
+{
+ return lhs.get() == rhs.get();
+}
+
+/**
+ * Compare two SGSharedPtr<T> objects for equality.
+ *
+ * @note Only pointer values are compared, not the actual objects they are
+ * pointing at.
+ */
+template<class T, class U>
+bool operator!=(const SGSharedPtr<T>& lhs, const SGSharedPtr<U>& rhs)
+{
+ return lhs.get() != rhs.get();
+}
+
+/**
+ * Compare two SGSharedPtr<T> objects for weak ordering.
+ *
+ * @note Only pointer values are compared, not the actual objects they are
+ * pointing at.
+ * @note This allows using SGSharedPtr as key in associative containers like for
+ * example std::map and std::set.
+ */
+template<class T, class U>
+bool operator<(const SGSharedPtr<T>& lhs, const SGSharedPtr<U>& rhs)
+{
+ return lhs.get() < rhs.get();
+}