diff --git a/src/include/strings.h b/src/include/strings.h
index 7fd64fb55..2c2fe60cf 100755
--- a/src/include/strings.h
+++ b/src/include/strings.h
@@ -654,8 +654,10 @@ public:
   void add(int n, int pos = -1);
   // @cmember Aggiunge un reale
   void add(const real r, int pos = -1);
-  // @cmember Aggiunge un reale
-  void add(const TDate d, int pos = -1);
+	// @cmember Aggiunge un reale
+	void add(const TDate d, int pos = -1);
+	// @cmember Aggiunge un booleano
+	void add(bool on, int pos = -1) { add(on ? "X" : ""); }
   // @cmember Inserisce una stringa
   void insert_at(const char* s, int n);
   // @cmember Toglie la stringa di posizione pos
diff --git a/src/include/utility.h b/src/include/utility.h
index 3320559ec..158a7e7c1 100755
--- a/src/include/utility.h
+++ b/src/include/utility.h
@@ -16,7 +16,7 @@
 #include <lffiles.h>
 
 #define STRINGIFY(x) #x
-#define SAFE_DELETE(p) { if( (p) != nullptr ) delete (p); (p) = nullptr; }
+#define SAFE_DELETE(p) safe_delete(p)
 #define TOSTRING(x) STRINGIFY(x)
 #define DEBUG_ENABLED is_debug_station()
 
@@ -24,6 +24,10 @@ bool    sirio_codesigning(const TFilename& filename, bool verify = false);
 #define SIRIOSIGN(filename) sirio_codesigning((const TFilename&)((filename)), false)
 #define SIRIOSIGN_VERIFY(filename) sirio_codesigning((const TFilename&)((filename)), true)
 
+template<typename T> void safe_delete(T*& a) {
+	delete a;
+	a = nullptr;
+}
 
 class TPerformance_profiler : public TObject
 {