Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!tut.cis.ohio-state.edu!cwang
From: cwang@tut.cis.ohio-state.edu (Chang-Jia Wang)
Newsgroups: comp.lang.c++
Subject: Return values of virtual functions
Keywords: virtual function
Message-ID: <77594@tut.cis.ohio-state.edu>
Date: 26 Feb 90 03:24:17 GMT
Distribution: na
Organization: Ohio State Univ Computer & Info Science
Lines: 14

I was using Zortech C++.

How can I have instances of a virtual function in a base class return
different type of values?  For example, suppose there are two classes of
matrices, IntMat and FloatMat, which are derived from a base class, Matrix.
A member function called Element(i,j) returns an element in a matrix.  The
function should return an int& in IntMat, but return a float& in FloatMat.

I cannot define a virtual function in Matrix because a virtual function
must return the same type of value as its derived classes do.  What tricks
should I use in order to call Matrix::Element(i,j), so a proper type of
value can be returned?

C.J.