[PING][PATCH v2 2/2] libstdc++: Use new built-in trait __is_signed

[Jonathan Wakely]

On Fri, 1 Sept 2023 at 14:01, Ken Matsui <kmatsui@cs.washington.edu> wrote:
>
> Ping for the use of __is_signed built-in.
>
> Sincerely,
> Ken Matsui
>
>
> On Wed, Jul 12, 2023 at 6:45 PM Ken Matsui <kmatsui@gcc.gnu.org> wrote:
> >
> > This patch lets libstdc++ use new built-in trait __is_signed.

OK for trunk after the built-in is approved for the compiler.


> >
> > libstdc++-v3/ChangeLog:
> >
> >         * include/std/type_traits (is_signed): Use __is_signed built-in trait.
> >         (is_signed_v): Likewise.
> >
> > Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
> > ---
> >  libstdc++-v3/include/std/type_traits | 15 ++++++++++++++-
> >  1 file changed, 14 insertions(+), 1 deletion(-)
> >
> > diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
> > index 0e7a9c9c7f3..23ab5a4b1e5 100644
> > --- a/libstdc++-v3/include/std/type_traits
> > +++ b/libstdc++-v3/include/std/type_traits
> > @@ -865,6 +865,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >      : public __bool_constant<__is_abstract(_Tp)>
> >      { };
> >
> > +  /// is_signed
> > +#if __has_builtin(__is_signed)
> > +  template<typename _Tp>
> > +    struct is_signed
> > +    : public __bool_constant<__is_signed(_Tp)>
> > +    { };
> > +#else
> >    /// @cond undocumented
> >    template<typename _Tp,
> >            bool = is_arithmetic<_Tp>::value>
> > @@ -877,11 +884,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >      { };
> >    /// @endcond
> >
> > -  /// is_signed
> >    template<typename _Tp>
> >      struct is_signed
> >      : public __is_signed_helper<_Tp>::type
> >      { };
> > +#endif
> >
> >    /// is_unsigned
> >    template<typename _Tp>
> > @@ -3240,8 +3247,14 @@ template <typename _Tp>
> >  template <typename _Tp>
> >    inline constexpr bool is_final_v = __is_final(_Tp);
> >
> > +#if __has_builtin(__is_signed)
> > +template <typename _Tp>
> > +  inline constexpr bool is_signed_v = __is_signed(_Tp);
> > +#else
> >  template <typename _Tp>
> >    inline constexpr bool is_signed_v = is_signed<_Tp>::value;
> > +#endif
> > +
> >  template <typename _Tp>
> >    inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;
> >
> > --
> > 2.41.0
> >
>