--- include/mdds/multi_type_matrix.hpp
+++ include/mdds/multi_type_matrix.hpp
@@ -149,7 +149,7 @@
 
 private:
     template<typename _Func>
-    struct walk_func : std::unary_function<typename store_type::const_iterator::value_type, void>
+    struct walk_func
     {
         _Func& m_func;
         walk_func(_Func& func) : m_func(func) {}
--- include/mdds/multi_type_vector.hpp
+++ include/mdds/multi_type_vector.hpp
@@ -139,7 +139,7 @@
         block& operator=(block);
     };
 
-    struct element_block_deleter : public std::unary_function<void, const element_block_type*>
+    struct element_block_deleter
     {
         void operator() (const element_block_type* p)
         {