diff --git a/Eigen/src/Core/util/Meta.h b/Eigen/src/Core/util/Meta.h
index 30ce0564d..4518261ef 100644
--- a/Eigen/src/Core/util/Meta.h
+++ b/Eigen/src/Core/util/Meta.h
@@ -83,8 +83,11 @@ template<> struct is_arithmetic<unsigned long> { enum { value = true }; };
 template<> struct is_arithmetic<signed long long>   { enum { value = true }; };
 template<> struct is_arithmetic<unsigned long long> { enum { value = true }; };
 
-template <class T> struct add_const { typedef const T type; };
-template <class T> struct add_const<T&> { typedef T& type; };
+template <typename T> struct add_const { typedef const T type; };
+template <typename T> struct add_const<T&> { typedef T& type; };
+
+template <typename T> struct is_const { enum { value = 0 }; };
+template <typename T> struct is_const<T const> { enum { value = 1 }; };
 
 template<typename T> struct add_const_on_value_type            { typedef const T type;  };
 template<typename T> struct add_const_on_value_type<T&>        { typedef T const& type; };