I have Block class that inherits from IKeyboardReader interface. I also have Keyboard class with a function that accepts a reference to IKeyboardReader interface. class Block : public (some other classes), IKeyboardReader; class Keyboard { void foo( IKeyboardReader& r ); } Now, I tried to pass an instance of Block class to this function but VS.NET 2002 gives me an error saying that conversion exists but is inaccessible. If I typecast it ( (IKeyboardReader&) ), the errors become warnings, but it still displays the same message. Not sure what's going on here.

Fruny, you are as helpful as you always are.