Ping for the use of __is_pointer built-in.
Sincerely,
Ken Matsui
On Thu, Jul 13, 2023 at 1:49 PM Ken Matsui wrote:
>
> This patch lets libstdc++ use new built-in trait __is_pointer.
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/cpp_type_traits.h (__is_ptr): Use __is_pointer
> built-in trait.
> * include/std/type_traits (is_pointer): Likewise. Optimize its
> implementation.
> (is_pointer_v): Likewise.
>
> Co-authored-by: Jonathan Wakely
> Signed-off-by: Ken Matsui
> ---
> libstdc++-v3/include/bits/cpp_type_traits.h | 8
> libstdc++-v3/include/std/type_traits| 44 +
> 2 files changed, 44 insertions(+), 8 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h
> b/libstdc++-v3/include/bits/cpp_type_traits.h
> index 3711e4be526..4da1e7c407c 100644
> --- a/libstdc++-v3/include/bits/cpp_type_traits.h
> +++ b/libstdc++-v3/include/bits/cpp_type_traits.h
> @@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
>//
>// Pointer types
>//
> +#if __has_builtin(__is_pointer)
> + template
> +struct __is_ptr : __truth_type<__is_pointer(_Tp)>
> +{
> + enum { __value = __is_pointer(_Tp) };
> +};
> +#else
>template
> struct __is_ptr
> {
> @@ -376,6 +383,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
>enum { __value = 1 };
>typedef __true_type __type;
> };
> +#endif
>
>//
>// An arithmetic type is an integer type or a floating point type
> diff --git a/libstdc++-v3/include/std/type_traits
> b/libstdc++-v3/include/std/type_traits
> index 0e7a9c9c7f3..16b2f6de536 100644
> --- a/libstdc++-v3/include/std/type_traits
> +++ b/libstdc++-v3/include/std/type_traits
> @@ -515,19 +515,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
> struct is_array<_Tp[]>
> : public true_type { };
>
> - template
> -struct __is_pointer_helper
> + /// is_pointer
> +#if __has_builtin(__is_pointer)
> + template
> +struct is_pointer
> +: public __bool_constant<__is_pointer(_Tp)>
> +{ };
> +#else
> + template
> +struct is_pointer
> : public false_type { };
>
>template
> -struct __is_pointer_helper<_Tp*>
> +struct is_pointer<_Tp*>
> : public true_type { };
>
> - /// is_pointer
>template
> -struct is_pointer
> -: public __is_pointer_helper<__remove_cv_t<_Tp>>::type
> -{ };
> +struct is_pointer<_Tp* const>
> +: public true_type { };
> +
> + template
> +struct is_pointer<_Tp* volatile>
> +: public true_type { };
> +
> + template
> +struct is_pointer<_Tp* const volatile>
> +: public true_type { };
> +#endif
>
>/// is_lvalue_reference
>template
> @@ -3168,8 +3182,22 @@ template
> template
>inline constexpr bool is_array_v<_Tp[_Num]> = true;
>
> +#if __has_builtin(__is_pointer)
> +template
> + inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> +#else
> template
> - inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
> + inline constexpr bool is_pointer_v = false;
> +template
> + inline constexpr bool is_pointer_v<_Tp*> = true;
> +template
> + inline constexpr bool is_pointer_v<_Tp* const> = true;
> +template
> + inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> +template
> + inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> +#endif
> +
> template
>inline constexpr bool is_lvalue_reference_v = false;
> template
> --
> 2.41.0
>
