Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!gatech!hubcap!ncrcae!ncr-sd!hp-sdd!hp-pcd!hplsla!jima
From: jima@hplsla.HP.COM (Jim Adcock)
Newsgroups: comp.lang.c++
Subject: Re: Some comments on Lippman's
Message-ID: <6590238@hplsla.HP.COM>
Date: 7 Sep 89 18:08:29 GMT
References: <PCG.89Sep6125146@thor.cs.aber.ac.uk>
Organization: HP Lake Stevens, WA
Lines: 54

// >Grandi: No mention is made of the newly overloadable "," operator. It would
// >be interesting to see cases in which it is useful.

//----------------------------------------------------------------

//Quick example of using <operator,> to make lists:

#include <stdio.h>

// This list class is really bogus -- its just a quick example!

class list
{
  const char *s;
  const list *l;
  const list *r;
public:
  list() {s=0; l=0; r=0;}
  list(const char *S){s=S; l=0; r=0;}
  list(const list& L, const list& R){s=0; l=&L; r=&R;}
  void print() const;
  list& operator,(const list& that){return *(new list(*this,that));}
};

void list::print() const
{
  if (l) l->print();
  if (s) printf("%s ",s);
  if (r) r->print();
}

void inline nextline(){putchar('\n');}

void main()
{

  list shoppinglist = (
    (list)
    "apples",
    "oranges",
    "celery",
    "bananas",
    "bread",
    "newspaper"
  );

  shoppinglist.print(); 

  nextline();

  ((list)"apples","oranges","celery","bananas","bread","newspaper").print();

  nextline();
}