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From: williamt@athena1.Sun.COM (William A. Turnbow)
Newsgroups: comp.lang.c++
Subject: Re: Is this a bug ?
Message-ID: <134460@sun.Eng.Sun.COM>
Date: 14 Apr 90 14:04:57 GMT
Sender: news@sun.Eng.Sun.COM
Reply-To: williamt@sun.UUCP (William A. Turnbow)
Lines: 26

In article <10259@shlump.nac.dec.com> nadkarni@ashok.dec.com writes:
>
>Am I doing something wrong or is this a bug in the compiler ? It appears 
>as though the compiler tries to optimize by not copying the virtual table
>function pointer when assigning an object to another. Unfortunately,
>in this case it does not work. The compiler is Zortech C++ 2.06.
>I expected to see the output
------
	Your program doesn't even compile on our compiler (AT&T 2.0.02).
It yields the following:
"tst8h.C", line 18: error:  member AB::b of class B with constructor in union
"tst8h.C", line 18: error:  member AB::c of class C with constructor in union
"tst8h.C", line 18: error:  member AB::a of class A with constructor in union
3 errors

	Just a guess, but there is a virtual field that gets auto initialized
when you declare an instance of the class.  By trying to do a union,
there would be three different constructors to call for the same memory
location, resulting in indeterminate behavior.  But this is just a
guess.

-wat-
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