diff --git rcore/aida.cc rcore/aida.cc
index ca69e5f..42b8de9 100644
--- rcore/aida.cc
+++ rcore/aida.cc
@@ -322,13 +322,13 @@ ImplicitBase::~ImplicitBase()
 RAPICORN_STATIC_ASSERT (sizeof (std::string) <= sizeof (Any)); // assert big enough Any impl
 
 Any::Any (const Any &clone) :
-  Any()
+  Any (Fix1())
 {
   this->operator= (clone);
 }
 
 Any::Any (Any &&other) :
-  Any()
+  Any (Fix1())
 {
   this->swap (other);
 }
diff --git rcore/aida.hh rcore/aida.hh
index b77ca2f..54a07aa 100644
--- rcore/aida.hh
+++ rcore/aida.hh
@@ -204,6 +204,7 @@ public:
 
 
 // == Any Type ==
+struct Fix1 {};
 class Any /// Generic value type that can hold values of all other types.
 {
   ///@cond
@@ -275,13 +276,13 @@ private:
   void    rekind  (TypeKind _kind);
 public:
   /*dtor*/ ~Any    ();                                  ///< Any destructor.
-  explicit  Any    ();                                  ///< Default initialize Any with no type.
+  explicit  Any    (const Fix1 &f = Fix1());            ///< Default initialize Any with no type.
   /// Initialize Any from a @a anany which is of Any or derived type.
   template<class V, REQUIRES< ::std::is_base_of< Any, typename std::remove_reference<V>::type >::value > = true> inline
-  explicit  Any (V &&anany) : Any()     { this->operator= (::std::forward<V> (anany)); }
+  explicit  Any (V &&anany) : Any (Fix1())     { this->operator= (::std::forward<V> (anany)); }
   /// Initialize Any and set its contents from @a value.
   template<class V, REQUIRES< !::std::is_base_of< Any, typename std::remove_reference<V>::type >::value > = true> inline
-  explicit  Any    (V &&value) : Any()  { set (::std::forward<V> (value)); }
+  explicit  Any    (V &&value) : Any (Fix1())  { set (::std::forward<V> (value)); }
   /*copy*/  Any    (const Any &clone);                  ///< Copy constructor.
   /*move*/  Any    (Any &&other);                       ///< Move constructor.
   Any& operator=   (const Any &clone);                  ///< Set @a this Any to a copy of @a clone.
@@ -755,7 +756,7 @@ struct ProtoScopeDisconnect : ProtoScope {
 
 // == inline implementations ==
 inline
-Any::Any() :
+Any::Any (const Fix1&) :
   type_kind_ (UNTYPED), u_ {0}
 {}