Introducing unique_ptrs to simplify memory management

common/statefunctional.cpp

@@ -301,6 +301,8 @@ double StateFunctional<T_Physic>::performance_regularization()
 template<Physic T_Physic>
 const ModelField& StateFunctional<T_Physic>::gradient()
 {
+    // Update the model adjoint state and return it.
+    // TODO: no model sent but FS is updated -> Is it always up to date ?
     std::array<bool,4> ToBeUpdated = {false,false,true,false};
     return _mu.get(ToBeUpdated).field(Type::AS);
 }