[Bug c++/93149] -fno-concepts silently ignored in c++2a mode

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93149

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-01-03
     Ever confirmed|0                           |1

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Since concepts have no runtime overhead I don't see any advantage to being able
to disable them. 


Arguably, since the option is documented as enabling the Concepts TS, we could
claim that -fno-concepts disables the TS, but leaves C++20 concepts enabled :-)

A warning saying it has no effect would make sense though.