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From: stuarth@csis.dit.csiro.au (Stuart Hungerford)
Newsgroups: comp.lang.c++
Subject: Can I make overloaded operator functions virtual?
Message-ID: <1991Mar20.074256.334@csis.dit.csiro.au>
Date: 20 Mar 91 07:42:56 GMT
Distribution: usa
Organization: csis.dit.csiro.au
Lines: 38

I'd like to be able to make overloaded operator functions virtual.  Say I
had this:

    class Base
    {
    public:
         virtual int operator== (const Base& B);
         //...
    };

then I'd like to override this virtual function in a derived class of Base.
BUT the language requires that overriding virtual functions requires an
exact match so I have to say:

    class Derived : public Base
    {
    public:
        int operator== (const Base& B);
        //...
    };

which means I'll probably end up casting Base classes to Derived ones in the
implementation of Derived::operator==.  I guess the same problem will hold
with any function that takes class references or pointers as arguments.

Am I missing something important here?  How do you handle this kind of 
situation? Any advice much appreciated.

Stuart

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