volatile [was: GCC warnings for unused global variables]

[Michael Eager]

Mike Stump wrote:
> On Saturday, May 3, 2003, at 09:50 AM, Michael Eager wrote:
> 
>> When I was on the C++ Standards Committee, I submitted a proposal which
>> was intended to make volatile well defined and explicit, rather than 
>> use the
>> vague definition inherited from C.  Unfortunately, the proposal was not
>> adopted.  A large part of the committee felt that volatile was an obscure
>> feature which did not need clarification.  The small part of the 
>> committee
>> which thought that volatile was important had the opinion that it 
>> would be
>> impossible (or at least very difficult) to define it precisely, 
>> although it
>> appeared that we all agreed on the same correct behavior for volatile.
> 
> 
> Hum.  My memory could be fading here, but I thought I was against it 
> because there was at least one wrong thing (IMHO) in how you defined it 
> at the time, and I thought the status quo was better than a status wrong.

I don't recall any specific suggestions for changes to the proposal, but
then again, this was a while ago.  I withdrew the proposal when it became
apparent that there was limited interest in working out any differences.
The status quo is that volatile is not defined.

As I've said, there seems to be many opinions about what volatile means.
I'm sure that any proposal attempting to define volatile would generate
significant discussion.  I'm not sure that it would be possible to arrive
at a consensus, though.

> Anyway, I think it would be great if you'd put up your work on volatile 
> up on a web site, and solicit feedback, and fix/expand/explain it for 
> folks.  If the nits of it are fixed, I think it would be good to have in 
> the language standards for C/C++.  Also, we can link it from the gcc web 
> site for those that would like a more complete explanation of volatile.

I don't know whether I still have the proposal.  I'll see if I can do this.


-- 
Michael Eager	 Eager Consulting     eager@eagercon.com
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