[Bug c++/83083] New: c++2a concepts without -fconcepts

[h2+bugs at fsfe dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83083

            Bug ID: 83083
           Summary: c++2a concepts without -fconcepts
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: h2+bugs at fsfe dot org
  Target Milestone: ---

Currently GCC offers the Concepts TS via -fconcepts, but it doesn't seem to
offer the modified/reduced Concepts merged into C++2a. For forward
compatibility checks of existing code and also for comparison with other
compilers (which will hopefully start supporting C++2a concepts sometime next
year), it would very, very helpful if GCC8 provided the new
concepts-light-light via the regular -std=c++2a switch (without -fconcepts).

Is this a planned feature or not a priority? Will it make it into GCC8? I know
these things are not trivial, but it seems like it's "only" a subset of already
existing features that "just" needs to be rewired.

Thanks a lot for your work on this!