On Fri, Jun 9, 2023 at 10:54 AM Patrick Palka <ppa...@redhat.com> wrote:
>
> On Sun, 2 Apr 2023, Ken Matsui via Gcc-patches wrote:
>
> > This patch gets std::is_function to dispatch to new built-in trait
> > __is_function.
>
> For std::is_function and other predicate-like type traits, I think we also
> want to make the corresponding variable template is_function_v directly
> use the built-in too.
Oh, thank you! Will implement it!
> >
> > libstdc++-v3/ChangeLog:
> >
> > * include/std/type_traits (is_function): Use __is_function built-in
> > trait.
> >
> > Signed-off-by: Ken Matsui <kmat...@cs.washington.edu>
> > ---
> > libstdc++-v3/include/std/type_traits | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/libstdc++-v3/include/std/type_traits
> > b/libstdc++-v3/include/std/type_traits
> > index 58a732735c8..9eafd6b16f2 100644
> > --- a/libstdc++-v3/include/std/type_traits
> > +++ b/libstdc++-v3/include/std/type_traits
> > @@ -594,6 +594,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > { };
> >
> > /// is_function
> > +#if __has_builtin(__is_function)
> > + template<typename _Tp>
> > + struct is_function
> > + : public __bool_constant<__is_function(_Tp)>
> > + { };
> > +#else
> > template<typename _Tp>
> > struct is_function
> > : public __bool_constant<!is_const<const _Tp>::value> { };
> > @@ -605,6 +611,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> > template<typename _Tp>
> > struct is_function<_Tp&&>
> > : public false_type { };
> > +#endif
> >
> > #define __cpp_lib_is_null_pointer 201309L
> >
> > --
> > 2.40.0
> >
> >
>
