Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!snorkelwacker.mit.edu!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!stc!inset!mikeb From: mikeb@inset.UUCP (Mike Banahan) Newsgroups: comp.std.c++ Subject: Re: What is int &volatile r; [Was: What is int &const r;] Message-ID: <1653@inset.UUCP> Date: 22 Apr 91 18:48:14 GMT Article-I.D.: inset.1653 References: Reply-To: mikeb@inset.co.uk (Mike Banahan) Distribution: comp Organization: The Instruction Set Ltd., London, UK. Lines: 20 ... what is "int & volatile .. " ... A good question to ask! A volatile reference to (exactly what doesn't matter) - if we were talking about C, and using a pointer, then it would mean that the value of the pointer was subject to unpredictable external change which cannot be discovered by simply reading the program; this is intended to allow for interrupts and concurrency to be implemented. Since a reference is not modifiable by the program (it's const), the utility of having a volatile one is severely questionable, but undoubtedly capable of implementation. One could imagine a globally-visible reference which is somehow updated by an interrupt routine to refer to various different objects at run-time. This makes me want to throw up, but that's what it mean by analogy with pointer types. If one of my guys did that with a reference, I daren't put in writing what I would want to do with him/her. Mike Banahan -- Mike Banahan, Founder Director, The Instruction Set Ltd. mikeb@inset.co.uk