https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120969
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Frank Heckenbach from comment #5)
> I never used "-fconcepts-ts" until now that GCC forces me to.
Not exactly. The code was accepted by accident in GCC 12 with C++20 and then
finally was rejected correctly in GCC 14. It was only by accident because it
was part of the original concept paper and was finally noticed it should be
removed.
So basically you were using some experimental part of GCC which was never
claimed as being finished and now GCC is correctly having it under
-fconcepts-ts and removing the support there you are complaining.
Again the C++20 support in GCC is still not fully complete (it is closer). So
there will be bugs.
Your code is invalid C++ 20 code even and you are complaining that GCC is
forcing you to use the -fconcepts-ts option for that purpose?
This is all hashed out in
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120917#c5 .
Again GCC never declared it fully supports C++20 in either GCC 12, 13 or 14. It
comes closest in GCC 15 though. The library side of C++20 (libstdc++) is still
considered experimental even. So if you depend on that backwards compatibility
is not guaranteed.
