https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69922
--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Stephan Bergmann from comment #0)
> With trunk@233631:
>
> > $ cat test.cc
> > struct S2 { virtual ~S2(); };
> > struct S1 {
> > virtual ~S1();
> > S2 * f(bool);
> > };
> > struct S3: S1, S2 {};
> > S2 * S1::f(bool b) { return b ? static_cast<S3 *>(this) : nullptr; }
>
> > $ g++ -Werror -Wnonnull-compare -c test.cc
> > test.cc: In member function ‘S2* S1::f(bool)’:
> > test.cc:7:59: error: nonnull argument ‘this’ compared to NULL
> > [-Werror=nonnull-compare]
> > S2 * S1::f(bool b) { return b ? static_cast<S3 *>(this) : nullptr; }
> > ^~~~~~~
> > cc1plus: all warnings being treated as errors
BTW, this style of posting (quoting the code) makes copy&pasting it
unnecessary hard. Please avoid it in the future.
