https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66918
--- Comment #6 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #5)
> I don't think the C++ FE has this warning; it's about C99 inlines.
If not, it has a very similar warning:
/home/manuel/test.cc:1:13: warning: inline function ‘void test()’ used but
never defined
inline void test(void);
^
