Path: utzoo!utgpu!jarvis.csri.toronto.edu!dgp.toronto.edu!flaps
Newsgroups: comp.lang.c
From: flaps@dgp.toronto.edu (Alan J Rosenthal)
Subject: Re: Write-only variables
Message-ID: <1989Sep14.183749.12753@jarvis.csri.toronto.edu>
References: <561@tigger.planet.bt.co.uk>
Date: 14 Sep 89 22:37:49 GMT

raph@tigger.planet.bt.co.uk (Raphael Mankin) writes:
>How does one declare write-only variables in C?
[ explanation of the use of write-only variables deleted ]

You cannot write to a variable in C without having an lvalue expression for
that variable.
All lvalue expressions in C have meaning as rvalues.%
Therefore, you cannot declare write-only variables in C.
(I think :-))

You can't even fake it with a macro, I don't think.
(Like "#define x (x_real + 0)" for faking const.)

ajr

% humourously, in ansi C, not all lvalue expressions in C have meaning as
lvalues (namely, array names).