From: gsm77 AT aol DOT com (GSM77)
Newsgroups: comp.os.msdos.djgpp
Subject: Incomprehensible Warning (He's back ...)
Date: 8 Jun 1998 16:02:38 GMT
Lines: 50
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To: djgpp AT delorie DOT com
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Ok, more of you don't know the "static_cast"
But the code which follow produce the same warning,
that I don't understand (may be 'cause I'm french ... ).

the code :
==========================
#include <fstream.h>

class X
  {
  int data;
  public:

  friend istream & operator >> (istream & , X & );
  };

class Y
    : public X
  {
  int OtherData;
  public:

  friend istream & operator >> (istream & , Y & );
  };


istream & operator >> (istream & os, X & me)
  {
   return os >> me.data;
  }

istream & operator >> (istream & os, Y & me)
  {
   os >> (X)me;                         /* This line produce the warning */
   os >> me.OtherData;
  }
==========================

produce the warning :
===================================================
In function `class istream & operator >>(class istream &, class Y &)':
Warning: initialization of non-const reference `class X &' from rvalue `X'
Warning: in passing argument 2 of `operator >>(istream &, X &)'
===================================================

I know that it's only a warning, but i learnt they often hide huge fooleries.
Does anyone have any idea ?, or explanation for a poor frenchy ...          :-(

                                                             Kamy.