Path: utzoo!attcan!uunet!ateng!chip
From: chip@ateng.uucp (Chip Salzenberg)
Newsgroups: comp.lang.c++
Subject: Re: Friend specifier considered harmful
Message-ID: <1988Sep15.151514.20657@ateng.uucp>
Date: 15 Sep 88 19:15:07 GMT
References: <61@cybaswan.UUCP> <1988Sep2.174327.6439@ateng.uucp> <78@cybaswan.UUCP>
Reply-To: chip@ateng.UUCP (Chip Salzenberg)
Organization: A T Engineering, Tampa, FL
Lines: 28

According to eeartym@cybaswan.UUCP (Dr R. Artym):
>chip@ateng.uucp (Chip Salzenberg) writes:
>> The HashTable class contains an array of pointers to HashNode.  Each
>> HashNode contains a pointer to the next HashNode.  I made HashTable a friend
>> of HashNode.  This allowed easy access to the HashNode "next" pointer but
>> _only_ for HashTable member functions.
>
>I see no reason why the HashTable can't request the preceding HashNode to
>place the new HashNode pointer in its next field.

Of course, I could have done it that way.  But I chose the "friendly"
approach so that other classes besides HashTable couldn't even _see_ the
next pointer, much less modify it.

>Why this structure anyway?  --- it's the C approach, not C++!  You ought to
>have an array of lists in HashTable, with the lists carrying HashNode objects
>without a next field.

But you're wrong!  Linked lists are a useful data structure no matter what
the language.

...Although I find it interesting that the interface I used would permit
changing to arrays instead of linked lists without modifying the HashTable
interface at all.  This is a good sign.
-- 
Chip Salzenberg                <chip@ateng.uu.net> or <uunet!ateng!chip>
A T Engineering                My employer may or may not agree with me.
	  The urgent leaves no time for the important.