Re: [Patch] Inline Variables for the Standard Library (p0607r0)

["Daniel Krügler" <daniel.kruegler@gmail.com>]

2017-03-11 21:23 GMT+01:00 Tim Song <t.canens.cpp@gmail.com>:
> On Sat, Mar 11, 2017 at 1:32 PM, Daniel Krügler
> <daniel.kruegler@gmail.com> wrote:
>> This patch applies inline to all namespace scope const variables
>> according to options A and B2 voted in during the Kona meeting, see:
>>
>> http://wiki.edg.com/pub/Wg21kona2017/StrawPolls/p0607r0.html
>>
>> During that work it has been found that std::ignore was not declared
>> constexpr (http://cplusplus.github.io/LWG/lwg-defects.html#2773),
>> which was fixed as well.
>
> Just adding constexpr to std::ignore does ~nothing. The assignment
> operator needs to be made constexpr too; there is really no other
> reason to use std::ignore.

There is nothing in the resolution of the issue (Nor in the discussion
that argues for the change) that says so. Yes, I considered to make
the assignment function template constexpr, but decided against it,
because the wording of the issue doesn't have this requirement). I'm
also aware of a test-case which would show the difference, but again:
This was not what the issue said. In fact I'm in the process to open a
new library issue that should impose that additional requirement.

- Daniel