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From: Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: does char *str="abcd"; alloc addressable memory?
Date: Sat, 11 Jul 2020 13:39:17 -0700
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James Kuyper <jameskuyper@alumni.caltech.edu> writes:
> On 7/10/20 11:09 PM, John Forkosh wrote:
> ...
>> I seem to recall, from long ago, that it was possible to accidentally
>> (or on purpose, though I don't recall ever seeing/hearing of any good
>> algorithmic reason to) change the value of numeric constants so that
>> afterwards, e.g., i=1;i+=1;(not sure about i++) results in i==3.
>
> What you're describing was certainly true of Fortran, and possibly other
> languages, but C has never worked that way.

I vaguely recall that VAXC, an old compiler for VAX/VMS, allowed
taking the address of a floating-point constant, so that for example
&1.2 would yield a value of type double*.  I have no idea what would
happen if you tried to modify the object via that pointer value.
It was never part of the C language, and I was surprised to see it
(around 1998 or so).  Fortunately we had the newer DECC compiler
as well.

This compiler was so out of date that if you wrote `x=-1`, it would
issue a warning about "-=" being ambiguous and then interpret it
as if you had written `x -= 1`.  The old "-=" syntax for compound
assignment operators is listed as obsolescent in K&R1, 1978.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */