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From: frei@mez.e-technik.uni-bochum.de (Matthias Frei)
Newsgroups: comp.lang.c++
Subject: Re: C++ 2.0 Question -- Whats wrong with this code ??
Message-ID: <297@mez.e-technik.uni-bochum.de>
Date: 19 Oct 89 08:06:18 GMT
References: <981@odin.SGI.COM>
Organization: Ruhr Universitaet Bochum, W-Germany
Lines: 26

mtoy@sgi.com (Michael Toy) writes:


>1	class Base {
>2	public:
>3	BaseClass();
>4	};
>5	extern TakesOne(BaseClass*&);
  ...
>10		TakesOne(this);
>11	}

>This causes C++2.0 to tell me "reference to const object" on line 10

Well, "this" is a const pointer to an object. If you pass "this" to
TakesOne() is a reference, it could be manipulated outside of 
the class base, possibly leading to inconsistencies.

You can avoid it by declaring
  extern TakesOne(const BaseClass* &)

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