Newsgroups: comp.lang.fortran
Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!alchemy.chem.utoronto.ca!mroussel
From: mroussel@alchemy.chem.utoronto.ca (Marc Roussel)
Subject: Re: Pseudo-FORTRAN -- f2c for the Macintosh
Message-ID: <1991Jun5.220805.4653@alchemy.chem.utoronto.ca>
Organization: Department of Chemistry, University of Toronto
References: <1991May30.040829.8696@eplrx7.uucp> <1017@DIALix.oz.au> <1991Jun1.171914.802@weyrich.UUCP>
Date: Wed, 5 Jun 1991 22:08:05 GMT

In article <1991Jun1.171914.802@weyrich.UUCP> orville@weyrich.UUCP
(Orville R. Weyrich) writes:
[on using EQUIVALENCE with variables of differing types]
>This leads to the $500,000 question: do algorithms exist which can do something
>intelligent with such uses of EQUIVALENCE?
>
>YES, I WOULD BE VERY INTERESTED IN THE ANSWER TO THE ABOVE QUESTION.

I can see one possible legitimate use of EQUIVALENCE with different data
types: to decide on the endianism of your machine (and similarly to decide
other quirks of the number system of the computer).  You can load up some
variables with known values, equivalence them to appropriate-sized integers
and then use these integers to diagnose the endianism (round-off, etc.).  Such
diagnostic toolkits are probably the only legitimate use of equivalence
across data types though (other than saving space).  Anyone know any others?

				Marc R. Roussel
                                mroussel@alchemy.chem.utoronto.ca