How to test if object has an exact type

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#8133

From: David Crocker
Date: Fri, 20 Apr 2001 13:24

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I have a requirement to distinguish at run-time whether a variable X is
exactly of some type T as opposed to being of some type derived from T. I
have to assume that T might be extended by an ignorant third party, so
defining a virtual function in T and then overridding it in all descendents
of T is not an option.

What is the best way of doing this? I know I can use getClass() to get the
Class object of the run-time type of X, but is there an efficient way to get
the Class object that corresponds to T? So far the best I can come up with
is to declare within class T the following:

   static const Class myClass = Class.forName("T");

then I can express the test as "X.getClass() == T.myClass".

Is there a better way? Does Java provide any other way of obtaining the
Class object for a given type? Any other ideas or advice will be
appreciated.

Dave Crocker, Escher Technologies Ltd.

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From: "David Crocker" <dcrocker@imsltd.com>
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Subject: How to test if object has an exact type
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