diff --git a/settable.hpp b/settable.hpp
index 3a9f975..1ec95b2 100644
--- a/settable.hpp
+++ b/settable.hpp
@@ -37,23 +37,19 @@ public:
 template<typename T>
 class setter: public abstract_setter {
 public:
-    setter(void *p)
-        : ptr(p) {
-        BOOST_ASSERT(ptr != 0);
+    explicit setter(T &object)
+        : reference(object) {
     }
 
     virtual void set_value(const std::string &value) {
-        T *ptrT = static_cast<T*>(ptr);
-        BOOST_ASSERT(ptrT != 0);
-
-        *ptrT = string2type::convert<T>(value);
+        reference = string2type::convert<T>(value);
     }
 
-    void *ptr;
+    T &reference;
 };
 
 #define REGISTER_MEMBER(Type, Attribute) \
-    this->register_setter<Type>(#Attribute, &Attribute);
+    this->register_setter<Type>(#Attribute, this->Attribute);
 
 class settable {
 public:
@@ -66,7 +62,7 @@ public:
     }
 
     template<typename T>
-    void register_setter(const std::string &name, T *ptr) {
+    void register_setter(const std::string &name, T &ptr) {
         typedef setter<T> specific_setter;
 
         setter_ptr setter(new specific_setter(ptr));