https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52763
--- Comment #10 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Martin Sebor from comment #8)
> Clang warns when an enum object is compared to a constant that's out of the
> most restricted range of the enum's type. The warning is in -Wall. It
> doesn't warn when the object is compared to a constant that doesn't
> correspond to any of the type's enumerators. I can see that being useful to
> some (carefully written) projects but suspect it could be quite noisy for
> many others.
>
> $ cat t.C && clang++ -S -Wall -Wextra t.C
> enum E { NONE = 0, ONE = 1, TWO = 2 };
>
> bool f (E e)
> {
> return e == 3; // no warning here
> }
>
> bool g (E e)
> {
> return e == 4;
> }
>
>
> t.C:10:12: warning: comparison of constant 4 with expression of type 'E' is
> always false [-Wtautological-constant-out-of-range-compare]
> return e == 4;
> ~ ^ ~
> 1 warning generated.
Would it make sense for GCC to just reuse -Wenum-compare for this case instead
of adding a new -Wtautological-constant-out-of-range-compare flag?
