Do we anticipate implementations actually providing a chimera of
different concepts proposals? Does any implementation already do so?

I would prefer to have only the one macro that indicates simply
whether we have TS concepts or standard concepts, and to not split the
hair any further unless there's actually a need to do so.

On Fri, 1 Mar 2019 at 14:51, Hubert Tong
<hubert.reinterpretcast_at_[hidden]> wrote:
>
> I believe these are meaningful as base values assuming an implementation is far enough along to set __cpp_concepts, covering `concept` versus `concept bool` and the atomic constraint matching through location + parameter mapping.
>
> __cpp_concepts: 201507 (TS) or 201707 (P0734).
> __cpp_requires_expr: 201507 (TS) or 201611 (P0266).
> __cpp_compound_req: 201507 (TS) or 201707 (P0734) or 201811 (P1084). Only 201507 allows placeholder types.
> __cpp_concept_placeholders: 201507 (TS) or 201811 (P1141).
>
> On Fri, Mar 1, 2019 at 4:26 PM John Spicer <jhs_at_[hidden]> wrote:
>>
>> [ Dropping core reflector ]
>>
>> Do you have a recommendation?
>>
>> John.
>>
>> On Mar 1, 2019, at 12:03 PM, Hubert Tong <hubert.reinterpretcast_at_[hidden]> wrote:
>>
>> I'm still hoping for some SG10 guidance on whether we want to query on what -> Concept does separately from whether Concept auto is available. There is also static_assert(C<T>) in the mix somewhere.
>>
>> -- HT
>>
>> On Fri, Mar 1, 2019 at 8:45 AM John Spicer <jhs_at_[hidden]> wrote:
>>>
>>> That seems appropriate to me (copying the core reflector).
>>>
>>> John.
>>>
>>> > On Mar 1, 2019, at 7:21 AM, Jonathan Wakely <cxx_at_[hidden]> wrote:
>>> >
>>> > The working draft doesn't specify a __cpp_concepts macro. I want to know if I need to say "concept bool" or just "concept", so I expected to be able to do:
>>> >
>>> > #if __cpp_concepts
>>> > template<typename T>
>>> > concept
>>> > #if __cpp_concepts <= 201507
>>> > bool
>>> > #endif
>>> > Foo = ...;
>>> > #endif
>>> >
>>> > Should this be handled by a core issue?
>>> >
>>> > _______________________________________________
>>> > Features mailing list
>>> > Features_at_[hidden]
>>> > http://www.open-std.org/mailman/listinfo/features
>>>
>>> _______________________________________________
>>> Features mailing list
>>> Features_at_[hidden]
>>> http://www.open-std.org/mailman/listinfo/features
>>
>>
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