GEEKING

Base/include/rbx/Declarations.h

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+#pragma once
+
+/*
+
+http://msdn.microsoft.com/en-us/magazine/cc301398.aspx
+
+	These days abstract classes are 
+not just common, they're ubiquitous. Think: where in Windows® do 
+abstract classes appear over and over again? That's right, in COM! 
+A COM interface is an abstract class with only pure virtual functions. 
+As everything in Windows migrates to COM land, Windows-based programs 
+have COM interfaces up the wazoo. A typical COM class might implement 
+a dozen or more interfaces, each with several functions.
+      Even outside COM, the notion of an interface is quite powerful 
+and useful, as in the Java language. Each interface implementation might 
+use several layers of classes, none intended to be used by themselves, 
+but only as base classes for yet more classes. ATL provides many such 
+classes using templates, another source of class proliferation. All of 
+this adds up to lots of initialization code and useless vtables with 
+NULL entries. The total bloat can become significant, especially when 
+you're developing small objects that must load over a slow medium like 
+the Internet. 
+  So __declspec(novtable) was invented to solve the problem. It's a 
+Microsoft-specific optimization hint that tells the compiler: this class 
+is never used by itself, but only as a base class for other classes, so 
+don't bother with all that vtable stuff, thank you.
+*/
+
+#ifdef _WIN32
+
+// Decoration to indicate a class is to be treated as an "Interface"
+// The class should contain pure virtual functions and maybe a little
+// trivial code. Otherwise, use RBXBaseClass.
+// !!! You can't define a virtual destructor for a class of this type
+#define RBXInterface	__declspec(novtable)
+
+// Decoration to indicate a class should not be instantiated directly
+// !!! You can't define a virtual destructor for a class of this type
+#define RBXBaseClass	__declspec(novtable)
+
+/****
+Note:
+
+C++ doesn't have a strict "Interface" type.  RBXInterface should be used
+for classes that declare only pure virtual functions and maybe a constructor
+and/or a field.  Classes that define non-trivial code should use RBXBaseClass instead.
+
+***/
+
+#else
+
+#define RBXInterface 
+#define RBXBaseClass 
+
+#endif
+
+