CComBool is a class to prevent the misuse of the VARIANT_BOOL type. VARIANT_BOOL is a problem because its legal values are -1 and 0 instead of 1 and 0, making converting back and forth between bool, BOOL and VARIANT_BOOL problematic. CComBool supports the constructors and operators needed to convert between the three C++ Windows Boolean types. It also supports operator& and CopyTo for common COM client and server usage. CComBool is available here.

The following table lists the various prices you pay for using the CRT and the default Win98 support in VC6. The builds were done with VC6, SP3, ATL COM in-proc server, no classes, no MFC, no merged p/s:

*Note: /opt:nowin98 is a VC6 linker switch that says not to align binaries on a Win98-friendly boundary. /opt:nowin98 builds will still load and run under Win98 without a problem, but the loading time could be longer. Also, when images get above 24KB, the /opt:nowin98 seems not to much of an affect on the size of the image.

Dharma Shukla and I wrote “Extending ATL3.0 Containment to Help You Write Real-World Containers” in the 12/99 issue of MSJ detailing how to add much-needed features to ATL’s support for control containment. Dharma wrote the sample code that accompanies the piece and has already made improvements to the code based on feedback. He’s maintaining the history and bits here.

Attila stands for “ATL for Applications.” Attila is a set of extensions built on top of ATL to provide application-level services in the same flavor as MFC. Towards that end, Attila uses a lot of the same notions as ATL, e.g. heavy use of templates, static binding and reliance on the compiler and the linker doing their job.  Also, in the flavor of ATL, Attila is under-documented and requires a lot of user investment to make use of it. However, once you do, we think you’ll find the flexibility and efficiency worth it. If you don’t, you haven’t lost much, ’cuz Attila is free. Enjoy.

The Simple Object II ATL ObjectWizard Extension (whew — I’ve got to come up with a shorter name…) provides the following features:

• Support for [oleautomation] interfaces.
• Support for the Neutral-threaded apartment.
• Support for IDispatch-based interfaces other than duals.
• Better support for disabling features that do not make sense together, e.g. FTM + ThreadingModel=Apartment.
• Updated pop-up help.

Originally, SimpleObject2 was built to do away with the one benefit of IDispatchImpl over IDelegatingDispImpl — wizard support. As do most things developed under the greedy eye of my colleagues, it grew to support a few more features than that. It’s available for download here. Enjoy. 

I got tired of not having a smart type for SAFEARRAYs, so I built one. It’s limited to one dimension (does anyone use multi-dimentional SAFEARRAYs?) and provides one class for the SAFEARRAY and another for the data itself (the lock is a resource, too), but the usage is pretty nifty. See comvector.h for the what and the how.

Also, Ron Jacobs sent me an ATL port of COleSafeArray called CComSafeArray that I’ve made available here.

This zip provides two classes for use with dates and times under Windows:

• CComDATE: Wraps the COM DATE type, providing conversions from VARIANT, DATE, ANSI string, UNICODE string, time_t, SYSTEMTIME, FILETIME, DOS time and DBTIMESTAMP data types.
• CComSpan: Represents the result of subtracting one CComDATE from another. Useful for time/date math.

If you’d like to know about how to expose multiple IDispatch implementations from a single COM object, check out this extensive treatment of that very topic.