[Bug c++/79301] With -Werror=pedantic outside C++17 mode, __has_cpp_attribute(fallthrough) is nonzero but [[fallthrough]] fails

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79301

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2017-02-08
                 CC|                            |msebor at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #1 from Martin Sebor <msebor at gcc dot gnu.org> ---
Interesting.  I'm not sure about how this would work with -Wpedantic
-Wno-error=pedantic.  I don't think there is a precedent for tying the behavior
of language features (or feature test macros) to -Werror settings.  I do agree,
though, that having the built-in return an affirmative result only to have the
compiler reject the feature seems to run counter to its intended purpose.  I'll
confirm this if only to see what others think.