NetNews Usenet Archive 1992 #20/NN_1992_20.iso/spool/comp/lang/cplus/13689

Internet Message Format | 1992-09-15 | 1.6 KB

Path: sparky!uunet!usc!sol.ctr.columbia.edu!lll-winken!sundance!moonshine!jac
From: [e-mail] (James A. Crotinger)
Newsgroups: comp.lang.c++
Subject: Re: Proposal: Subscripting with multiple arguments
Message-ID: <jac.716576376@moonshine>
Date: 15 Sep 92 16:59:36 GMT
References: <[e-mail]>     <[e-mail]> <[e-mail]>
Sender: [e-mail] (News Administrator)
Organization: Magnetic Fusion Energy - LLNL
Lines: 23

[e-mail] (Thomas M. Breuel) writes:
> What you can do, however, is to share a lot of code among the
> different array classes. For example, you might have your
> multidimensional array inherit from your 1D array.

  Not publicly, I hope. There is no "is a" relationship in that
direction. (Well, you can say that a 2D array of floats is a 1D array
of 1D arrays of floats, but that's not the same as inheritance since
the types of the 2D and "outer" 1D arrays are different.)  In one of
our class libraries we did implement "Vector" (1D array) as inheriting
from "Matrix" (2D array). This makes sense since a Vector is just a
Matrix with only 1 column. Thus you can safely pass a Vector to any
function which operates on Matrices, etc. You would not want to try to
do the reverse.

>                     Thomas.

  Jim
--
-------------------------------------------------/\--------------------------
James A. Crotinger     Lawrence Livermore N'Lab // \ The above views are mine
[e-mail] P.O. Box 808;  L-630 \\ //---\  and are not neces-
[phone]         Livermore CA  94550   \\/Amiga\  sarily those of LLNL.