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From: are@sinix.UUCP (Andreas Eder)
Newsgroups: comp.lang.c++
Subject: beginners question
Message-ID: <1991Jun5.090228.27147@sinix.UUCP>
Date: 5 Jun 91 09:02:28 GMT
Article-I.D.: sinix.1991Jun5.090228.27147
Sender: are@portland.sp4n1.siemens.de
Organization: SNI AG Muenchen, STO XS
Lines: 19

Hello experts,
I'm new to C++ and have the following problem:
I have several numeric types such as integers, rationals, reals etc. Now
I want a procedure to add to numbers that can add two numbers regardless
of the actual type. That is in some place of the code I have

number *a, *b;

where number is the base type of all the integers, rationals, etc..

Now I want a function number *add(number *, number *) that can add any two numbers. I now about virtual functions, but wouldn't that only work depending
on the type of the first variable. 
Now, how do I do this without switching on the type of the second parameter ?
Or do I have to include a type field in the class definition?
Any help is welcome.
Thank you,
Andreas

are@portland.sp4n1.siemens.de