Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!pdn!tscs!tct!chip
From: chip@tct.com (Chip Salzenberg)
Newsgroups: comp.lang.c++
Subject: Re: Implementing NULL
Message-ID: <28468FF0.44E5@tct.com>
Date: 31 May 91 18:03:28 GMT
References: <77091@brunix.UUCP>
Organization: Teltronics/TCT, Sarasota, FL
Lines: 21

According to sdm@cs.brown.edu (Scott Meyers):
>    class NullClass {
>      public:
>        template <class T> operator T*() const { return 0; }
>    };
>
>    extern NullClass NULL;

This approach loses when NULL is used for a non-class pointer.
For example, this code fragment won't work with NullClass:

    extern time_t time(time_t *t);

    main()
    {
        time_t t = time(NULL);
    }

-- 
Chip Salzenberg at Teltronics/TCT     <chip@tct.com>, <uunet!pdn!tct!chip>
          perl -e 'sub do { print "extinct!\n"; }   do do()'