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Comment by rseacord | Hacker News Reader

Many of your remaining questions have devolved into "When will I see my favorite feature xyz appear in the C Standard?" The answer in most cases is "that depends on how long it takes you to submit a proposal". Take a look at http://www.open-std.org/jtc1/sc22/wg14/www/wg14_document_log... for previous proposals and review the minutes to see which proposals have been adopted. In general, the committee is not going to adopt proposals for which there is insufficient existing practice or haven't been fully thought out. There are cases where people have come to a single meeting with a well-considered proposal that was adopted into the C Standard. I wrote about one such case here: https://www.linkedin.com/pulse/alignment-requirements-memory... Alternatively, you can approach someone on the committee and ask us to champion a proposal for you. It is likely that we'll agree or at least provide you with feedback on your proposal.

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Thanks to one and all for this AMA! The massive number of comments testifies to the continuing interest in C, and I think we're all grateful to all of you for your expertise, your patience, and your even-handed responses.

Is the present purpose of the Standard to:

1. define a highly-extensible abstraction model, which implementations intended for various purposes should be expected to extend to suit those purpose, or

2. define an abstraction model which is sufficiently complete that programs can do everything that would need to be done, without need for extensions?

Reading the C89 and C99 Rationale documents, it's clear that those standards were intended to meet the former purpose. The way some compilers treat "Undefined Behavior", however, suggests that the maintainers view the Standard as aimed toward the latter purpose.

During the 1980s and 1990s, it was generally cheaper and easier for implementations to extend the Standard's abstraction model by specifying that many actions would be processed "in a documented fashion characteristic of the environment" than it would have been to do anything else, so there was no need to worry about whether the Standard allowed programmers to specify when such behavior was required. That no longer holds true, however.

While it would be reasonable to deprecate code which relies upon such treatment without explicitly demanding it, such deprecation would only make sense if there were a means of demanding such treatment when required. For the Committee to provide such means, however, it would have to reach a consensus as to the purposes for which the Standard's abstraction model is meant to be suitable. Are you aware of any such consensus?

I don't know if you saw my question right below, since I guess I replied to the wrong post, but I'd be really interested to know how you view the purpose of the Standard. For years, the language has been caught in a catch-22 where the authors of the Standard have seen no need to have it recognize constructs that compilers have, almost unanimously, processed usefully for years without being required to do so, but some compiler maintainers interpret the failure to mandate such constructs as deprecation.

I would like to see the Standard either rewritten in such a way as to actually define (sometimes as optional features) everything necessary to make an implementation suitable for a wide range of tasks, or else expressly state that, e.g. "There are some circumstances where the behavior of some action would documented by parts of the Standard, the documentation of the implementation and execution environment, or other materials, but some other portions of the Standard would characterize those actions as invoking Undefined Behavior. This Standard expressly waives jurisdiction in such cases so as to allow implementations designed for a variety of purposes to process them in whatever fashion would best suit those purposes."

What would you think about including something like those last two sentences in the Standard, so as to help clarify its intention?

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