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Subject: [SG10] Comments from Alisdair
From: Nelson, Clark (clark.nelson_at_[hidden])
Date: 2014-05-15 18:13:05


I got a few comments today about SD-6 from Alisdair Meredith. Most of them
were just pointing out that it needs to be updated, which we already knew,
and which is in progress. But there are a few I thought I should pass along.

> We added an 'is_final' type-trait at the last meeting too, not
> sure what name to recommend (issue 2112) and 'is_null_pointer' at
> Chicago (issue 2247)
>
> We added 'make_reverse_iterator' to the <iterator> header (issue
> 2285)

It came as news to me that we, as a committee, have added features to the
standard in response to issues (a.k.a. defect reports). Obviously, those of
us who feel that's a bad idea in general might want to suggest that we be
more careful to avoid that in the future. :-(

But apparently we have some water under the bridge, and SG10 needs to decide
whether these should have macros.

> Finally, do we want a feature to detect that 'gets' has finally
> been removed? (NB comment GB 9 in N3733)

I'm not even going to try to frame this question. :-/ (This is library issue
2249, for anyone who wants more information.)

> Oh, and as a point of curiosity, it turned out that there is no
> feature-detect macro for the C++11 feature I am trying to detect,
> alias templates! I am surprised at just how useful I am finding
> this feature at the moment, but mostly as a porting aid, saying
> "this old code is now implemented using that new more
> general/standard feature over there" (plus implementing the few
> places that standard library mandates them).

Is there anyone who thinks that this would not be a good idea? (This was
adopted from N2258.)

--
Clark Nelson            Vice chair, PL22.16 (ANSI C++ standard committee)
Intel Corporation       Chair, SG10 (C++ SG for feature-testing)
clark.nelson_at_[hidden]  Chair, CPLEX (C SG for parallel language extensions)

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