signals 2.0

slot_base.h

@@ -0,0 +1,43 @@
+#ifndef __slot_base_h__
+#define __slot_base_h__
+
+class slot_base
+{
+	public:
+
+		slot_base ();  // constructor
+		virtual ~slot_base (); // destructor
+
+		/* Use compiler-generated copy constructor, assignment operator */
+
+		bool operator== (const slot_base& other) const;
+
+	protected:
+
+		// a generic type to hold a pointer, virtual method function pointer, etc.
+		struct data_container
+		{
+			// should be at least as large as the largest type you want
+			// to store in one of these
+			enum { SIZE_IN_WORDS = 4 };
+			enum { SIZE_IN_BYTES = SIZE_IN_WORDS*sizeof(unsigned int) };
+
+			// the actual storage space
+			unsigned int data[SIZE_IN_WORDS];
+
+			// an equality operator
+			bool operator== (const data_container& other) const;
+
+			// a method to set to empty (zero)
+			void zero();
+		};
+
+		// number of pointers, etc. we'll track in this class
+		enum { NUM_DATA_ITEMS = 2 };
+
+		// storage for function pointers, etc. hoisted out of derivative slots
+		data_container data[NUM_DATA_ITEMS];
+};
+
+#endif // __slot_base_h__
+