C++ Logo

SG10

Advanced search

Subject: Re: [isocpp-lib] __cpp_lib_unwrap_ref in wrong header
From: Jonathan Wakely (cxx_at_[hidden])
Date: 2019-12-02 04:44:46


On Sun, 1 Dec 2019 at 04:10, Barry Revzin via Lib <lib_at_[hidden]>
wrote:

> Hi SG10 and LWG,
>
> cpplearner points out in https://github.com/BRevzin/sd6/issues/1 that:
>
> "Since unwrap_reference and unwrap_ref_decay are defined in <functional>
> ([functional.syn]), their feature test macro should also be defined there."
>
> P1902R1 adds this feature test macro in <type_traits> instead. I agree
> with them - I think the choice of <type_traits> was my mistake.
>
>
Didn't I create an issue saying those traits *should* be in <type_traits>?
I think I meant to.

No, I complained about it in the
https://lists.isocpp.org/lib-ext/2019/04/11223.php thread but only fixed
the accidental application of the wrong paper (via the
https://cplusplus.github.io/LWG/issue3202 issue).

> Does anybody object to moving it to <functional>?
>
>
I'd rather move the traits to <type_traits>, but if we don't do that we
should move the macro.

In https://lists.isocpp.org/lib-ext/2019/04/11229.php I said "Does anybody
want to argue for keeping it in <functional>?" and nobody spoke up.

> Assuming no, what should the process of such a change involve? LWG issue?
>
>
I'll try to hijack that issue to move the traits ;-)



SG10 list run by herb.sutter at gmail.com