Re: ? Feature Detection ala JavaScript

"Igor Tandetnik" <>
Tue, 13 Jan 2009 19:25:54 -0500
Tamas Demjen <> wrote:

In JavaScript it is possible to detect features, eg:

  if (document.getElementById)

Others have already answered the C++ language aspect of your
question. I would like to discuss the special case of COM objects.

You can detect features of COM object from C++, as long as it
implements the IDispatch interface. After calling GetTypeInfo, you
can retrieve information about the interface, such as a list of
member functions and their parameters

Or, you could just call IDispatch::GetIdsOfNames to check whether the
object supports a given name as a property or method. Note that
JavaScript engine doesn't use type libraries, even when available.
With best wishes,
    Igor Tandetnik

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