ITypeLib Interface

The data that describes a set of objects is stored in a type library. A type library can be a stand-alone binary file (.tlb), a resource in a dynamic link library or executable file (.dll or .exe), or part of a compound document file.

Implemented by	Used by	Header file name
Oleaut32.dll (32-bit systems) Typelib.dll (16-bit systems)	Tools that need to access the descriptions of objects contained in type libraries.	Oleauto.h Dispatch.h

The system registry contains a list of all the installed type libraries. Type library organization is illustrated in the following figure:

The ITypeLib interface provides methods for accessing a library of type descriptions. This interface supports the following:

Generalized containment for type information. ITypeLib allows iteration over the type descriptions contained in the library.
Global functions and data. A type library can contain descriptions of a set of modules, each of which is the equivalent of a C or C++ source file that exports data and functions. The type library supports compiling references to the exported data and functions.
General information, including a user-readable name for the library and help for the library as a whole.