ODL: Microsoft Object Interface Definition
- Interface definition language, compiled by MKTYPLIB into Type
Libraries, that describes the contents of a DLL.
- Used by OLE to describe data structures, functions,
and their parameters.
- Unfortunatly, Microsoft uses two interface
definition languages, ODL for OLE, and MIDL
for COM. Fortunatly, the new version of Distributed
COM, in Windows NT version
4.0, has MIDL 3.0, which unifies the two languages,
so ODL is now obsolete.
- MKTYPLIB itself can accept any type you want to put in an OLE Automation
interface, including your own structs, enums, and unions. However, these
are not accepted in an automation-compatible interface which includes by
design any dispinterface. Furthermore, unsigned is not accepted for automation-compatible
interfaces, although you can use it anywhere else. (Inside OLE, Second Edition,