Abstract: A condition detected by a virtual routine may be treated by setting an error code or raising an exception, depending on circumstances. Enhanced vtable layouts promote availability of both error-ID-based and exception-based virtual routines, while maintaining compatibility. Compilers treat virtual routines based on their circumstances. One enhanced vtable includes error-ID-based routine pointers in a COM-layout-compatible portion and exception-based routine pointers in an extension. For a virtual routine not overridden by a derived class, a compiler generates a direct call. For an object instance of a specific type, the compiler generates a direct exception-based call for the object's routine. For a factory-sourced object's routine, the compiler generates a virtual exception-based call. When the virtual routine belongs to a component having an enhanced vtable, the compiler may generate a virtual call using the exception-based routine pointer. Code wrappers between COM and native format may also be used.

Abstract: A condition detected by a virtual routine may be treated by setting an error code or raising an exception, depending on circumstances. Enhanced vtable layouts promote availability of both error-ID-based and exception-based virtual routines, while maintaining compatibility. Compilers treat virtual routines based on their circumstances. One enhanced vtable includes error-ID-based routine pointers in a COM-layout-compatible portion and exception-based routine pointers in an extension. For a virtual routine not overridden by a derived class, a compiler generates a direct call. For an object instance of a specific type, the compiler generates a direct exception-based call for the object's routine. For a factory-sourced object's routine, the compiler generates a virtual exception-based call. When the virtual routine belongs to a component having an enhanced vtable, the compiler may generate a virtual call using the exception-based routine pointer. Code wrappers between COM and native format may also be used.

Abstract: Hosting user interface controls in a window via an interface for controlling the window is disclosed. One aspect of the invention is a computerized system having an operating system and at least one program. The operating system provides for hosting controls of a predetermined type within windows of a predetermined type via an interface for controlling the windows. The programs utilize the interface to host one or more controls within one or more windows. Thus, with respect to versions of the MICROSOFT WINDOWS operating system, a program may utilize the WIN32 API (i.e., interface) to host ACTIVEX-type controls within windows hosted by the program, also via the WIN32 API.