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From: kenner@lab.ultra.nyu.edu (Richard Kenner)
Subject: Re: Garbage Collection in Ada
Date: 1996/10/19
Message-ID: <54ak06$ms4@news.nyu.edu>#1/1
X-Deja-AN: 190574527
references: <19961016113936528855@dialup120-4-1.swipnet.se>
 <dewar.845470588@merv> <DzEC1x.34J@world.std.com>
organization: New York University Ultracomputer Research Lab
newsgroups: comp.lang.ada
Date: 1996-10-19T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <DzEC1x.34J@world.std.com> bobduff@world.std.com (Robert A Duff) writes:
>What does it mean to use virtual origins in C, given that all arrays
>start at zero?

The corresponding array on the Ada size *doesn't* start from zero, but
instead some large positive number.  We use the same index in C and Ada
by subtracting the lower bound from a pointer to the array in C.

This exactly corresponds to the use of virtual origins in C (and yes, it
isn't a legal ANSI C program).