Improved MethodBinder

libuavcan/include/uavcan/internal/method_binder.hpp

@@ -20,13 +20,9 @@ class MethodBinder
     ObjectPtr obj_;
     MemFunPtr fun_;
 
-public:
+    void validateBeforeCall() const
-    MethodBinder(ObjectPtr o, MemFunPtr f)
-    : obj_(o)
-    , fun_(f)
     {
-        if (!try_implicit_cast<bool>(o, true) ||
+        if (!operator bool())
-            !try_implicit_cast<bool>(f, true))
         {
 #if UAVCAN_EXCEPTIONS
             throw std::runtime_error(typeid(*this).name());
@@ -37,13 +33,41 @@ public:
         }
     }
 
-    void operator()() { (obj_->*fun_)(); }
+public:
+    MethodBinder()
+    : obj_()
+    , fun_()
+    { }
+
+    MethodBinder(ObjectPtr o, MemFunPtr f)
+    : obj_(o)
+    , fun_(f)
+    { }
+
+    operator bool() const
+    {
+        return try_implicit_cast<bool>(obj_, true) && try_implicit_cast<bool>(fun_, true);
+    }
+
+    void operator()()
+    {
+        validateBeforeCall();
+        (obj_->*fun_)();
+    }
 
     template <typename Par1>
-    void operator()(Par1 p1) { (obj_->*fun_)(p1); }
+    void operator()(Par1 p1)
+    {
+        validateBeforeCall();
+        (obj_->*fun_)(p1);
+    }
 
     template <typename Par1, typename Par2>
-    void operator()(Par1 p1, Par2 p2) { (obj_->*fun_)(p1, p2); }
+    void operator()(Par1 p1, Par2 p2)
+    {
+        validateBeforeCall();
+        (obj_->*fun_)(p1, p2);
+    }
 };
 
 }