Fixes to FunctionPointer and friends

mbed/FunctionPointer.h

@@ -28,7 +28,7 @@ namespace mbed {
 /** A class for storing and calling a pointer to a static or member void function
  */
 template <typename R>
-class FunctionPointer0 : protected FunctionPointerBase<R>{
+class FunctionPointer0 : public FunctionPointerBase<R>{
 public:
     typedef R(*static_fp)(void);
     typedef struct arg_struct{

mbed/FunctionPointerBase.h

@@ -29,11 +29,34 @@ class FunctionPointerBase {
         return (_membercaller != NULL) && (_object != NULL);
     }
 
+    /**
+     * Clears the current function pointer assignment
+     * After clear(), this instance will point to nothing (NULL)
+     */
+    virtual void clear() {
+        _membercaller = NULL;
+        _object = NULL;
+    }
+
+protected:
     struct ArgOps {
         void (*constructor)(void *, va_list);
         void (*copy_args)(void *, void *);
         void (*destructor)(void *);
     };
+    void * _object; // object Pointer/function pointer
+    R (*_membercaller)(void *, uintptr_t *, void *);
+    // aligned raw member function pointer storage - converted back by registered _membercaller
+    uintptr_t _member[4];
+    static const struct ArgOps _nullops;
+
+protected:
+    FunctionPointerBase():_object(NULL), _membercaller(NULL) {}
+    FunctionPointerBase(const FunctionPointerBase<R> & fp) {
+        copy(&fp);
+    }
+    virtual ~FunctionPointerBase() {
+    }
 
     /**
      * Calls the member pointed to by object::member or (function)object
@@ -43,18 +66,6 @@ class FunctionPointerBase {
     inline R call(void* arg) {
         return _membercaller(_object, _member, arg);
     }
-protected:
-    FunctionPointerBase():_object(NULL), _membercaller(NULL) {}
-    FunctionPointerBase(const FunctionPointerBase<R> & fp) {
-        copy(&fp);
-    }
-    static const struct ArgOps _nullops;
-
-protected:
-    void * _object; // object Pointer/function pointer
-    R (*_membercaller)(void *, uintptr_t *, void *);
-    // aligned raw member function pointer storage - converted back by registered _membercaller
-    uintptr_t _member[4];
 
     void copy(const FunctionPointerBase<R> * fp) {
         _object = fp->_object;

mbed/FunctionPointerBind.h

@@ -36,7 +36,7 @@
 namespace mbed{
 
 template<typename R>
-class FunctionPointerBind : FunctionPointerBase<R> {
+class FunctionPointerBind : public FunctionPointerBase<R> {
 public:
     // Call the Event
     inline R call() {
@@ -46,12 +46,13 @@ class FunctionPointerBind : FunctionPointerBase<R> {
         FunctionPointerBase<R>(),
         _ops(&FunctionPointerBase<R>::_nullops)
     {}
+
     FunctionPointerBind(const FunctionPointerBind<R> & fp):
         FunctionPointerBase<R>(),
-        _ops(&FunctionPointerBase<R>::_nullops)
-    {
+        _ops(&FunctionPointerBase<R>::_nullops) {
         *this = fp;
     }
+
     ~FunctionPointerBind() {
         _ops->destructor(_storage);
     }
@@ -66,6 +67,21 @@ class FunctionPointerBind : FunctionPointerBase<R> {
         return *this;
     }
 
+    R operator ()() {
+        return call();
+    }
+
+    /**
+     * Clears the current binding, making this instance unbound
+     */
+    virtual void clear() {
+        if (_ops != &FunctionPointerBase<R>::_nullops) {
+            _ops->destructor(_storage);
+        }
+        _ops = &FunctionPointerBase<R>::_nullops;
+        FunctionPointerBase<R>::clear();
+    }
+
     template<typename S>
     FunctionPointerBind<R> & bind(const struct FunctionPointerBase<R>::ArgOps * ops , S * argStruct, FunctionPointerBase<R> *fp, ...) {
         MBED_STATIC_ASSERT(sizeof(S) <= sizeof(_storage), ERROR: Arguments too large for FunctionPointerBind internal storage)