Add pointer specialization for value_less

include/boost/intrusive/detail/value_functors.hpp

@@ -18,6 +18,8 @@
 #  pragma once
 #endif
 
+#include <cstddef>
+
 namespace boost {
 namespace intrusive {
 
@@ -29,6 +31,14 @@ struct value_less
       {  return a < b;  }
 };
 
+//Functors for member algorithm defaults
+template<class T>
+struct value_less<T*>
+{
+   bool operator()(const T *a, const T* b) const
+      {  return std::size_t(a) < std::size_t(b);  }
+};
+
 template<class ValueType>
 struct value_equal
 {