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From: marti@ethz.UUCP (Robert Marti)
Newsgroups: comp.lang.c++
Subject: "Inheritance" of operator=()
Keywords: user error or cfront error?
Message-ID: <863@ethz.UUCP>
Date: 10 May 89 12:13:57 GMT
Organization: ETH Zuerich
Lines: 54

Disclaimer:  I am fairly new at trying out some things in C++, so don't
flame me if I overlooked something obvious.

The following code gives an error on the line indicated with <<<<< when
compiled on a Sun-3/50, SunOS 4.0.1, with cfront 1.2.1.

=====
struct ObjDescr {
  void* val;
  int ref_count;
};

class Object {
protected:
  ObjDescr* obj;
public:
  Object();
  Object(Object& another);
  void operator=(Object& another);
  virtual ~Object();
  virtual int operator==(Object& another);
};

class IntObj : public Object {
public:
  IntObj();
  IntObj(int i);
  int operator==(Object& another);
  operator Object();
};

// definitions of Object:: and IntObj:: member functions ...

main()
{
  IntObj o;
  IntObj o1 = 1;
  IntObj o2 = 2;

  o = o1;  // <<<<< error: assignment not defined for class IntObj
  o.operator=(o2);
}
=====

Why is this?  The "bible" somewhere states that x operator@ y
is equivalent (among other things) to x.operator@(y), so I feel
that cfront should figure out in both cases that I want the
"inherited" member function Object::operator= for the IntObj o ...

-- 
Robert Marti                      Phone:      +41 1 256 52 36
Institut fur Informationssysteme
ETH-Zentrum                       CSNET/ARPA: marti%inf.ethz.ch@relay.cs.net
CH-8092 Zurich, Switzerland       UUCP:       ...uunet!mcvax!ethz!marti