Newsgroups: comp.lang.c
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Whither _noalias_?
Message-ID: <1991Feb9.051404.8297@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <ENAG.91Jan14003710@svarte.ifi.uio.no> <1991Feb7.050917.24550@zoo.toronto.edu> <1991Feb8.211734.22306@portia.Stanford.EDU>
Date: Sat, 9 Feb 1991 05:14:04 GMT

In article <1991Feb8.211734.22306@portia.Stanford.EDU> dhinds@elaine24.stanford.edu (David Hinds) writes:
>    That's a shame...  Was it really that hard
>to come up with a clear and useful definition of "noalias", or was it just
>a result of committee politics fouling it up?  Was the proposal to just
>have "noalias" apply to function parameters? ...

"noalias" was a qualifier, like "const" and "volatile", and could be applied
to most anything.  This may have been too ambitious, in retrospect.  Doing
something with function parameters and *only* function parameters might
have been inoffensive enough to get by.  (In fact, the standard lists as
a "future direction" the possibility that declaring more than one parameter
as an array -- remember that this is pointless today, since array parameters
are really pointer parameters and might as well be written as such -- might
someday come to mean "these are not aliases of each other".)

I think it was exceedingly difficult to come up with a decent definition
of "noalias", given its generality and the qualifier rules then in effect.
Some very sharp people tried hard, since it was generally agreed that
there *was* a real need.
-- 
"Maybe we should tell the truth?"      | Henry Spencer at U of Toronto Zoology
"Surely we aren't that desperate yet." |  henry@zoo.toronto.edu   utzoo!henry
