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 <[email protected]> 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 <[email protected]> wrote: >> >> [ Dropping core reflector ] >> >> Do you have a recommendation? >> >> John. >> >> On Mar 1, 2019, at 12:03 PM, Hubert Tong <[email protected]> >> 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 <[email protected]> wrote: >>> >>> That seems appropriate to me (copying the core reflector). >>> >>> John. >>> >>> > On Mar 1, 2019, at 7:21 AM, Jonathan Wakely <[email protected]> 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 >>> > [email protected] >>> > http://www.open-std.org/mailman/listinfo/features >>> >>> _______________________________________________ >>> Features mailing list >>> [email protected] >>> http://www.open-std.org/mailman/listinfo/features >> >> > _______________________________________________ > Features mailing list > [email protected] > http://www.open-std.org/mailman/listinfo/features _______________________________________________ Features mailing list [email protected] http://www.open-std.org/mailman/listinfo/features
