[v2,1/2] c++, libstdc++: implement __is_pointer built-in trait

Message ID 20230710053828.49793-1-kmatsui@gcc.gnu.org
State Accepted
Headers
Series [v2,1/2] c++, libstdc++: implement __is_pointer built-in trait |

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Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Ken Matsui July 10, 2023, 5:38 a.m. UTC
  This patch implements built-in trait for std::is_pointer.

gcc/cp/ChangeLog:

	* cp-trait.def: Define __is_pointer.
	* constraint.cc (diagnose_trait_expr): Handle CPTK_IS_POINTER.
	* semantics.cc (trait_expr_value): Likewise.
	(finish_trait_expr): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/has-builtin-1.C: Test existence of __is_pointer.
	* g++.dg/ext/is_pointer.C: New test.
	* g++.dg/tm/pr46567.C (__is_pointer): Rename to ...
	(____is_pointer): ... this.
	* g++.dg/torture/20070621-1.C: Likewise.
	* g++.dg/torture/pr57107.C: Likewise.

libstdc++-v3/ChangeLog:

	* include/bits/cpp_type_traits.h (__is_pointer): Rename to ...
	(____is_pointer): ... this.
	* include/bits/deque.tcc: Use ____is_pointer instead.
	* include/bits/stl_algobase.h: Likewise.

Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
 gcc/cp/constraint.cc                        |  3 ++
 gcc/cp/cp-trait.def                         |  1 +
 gcc/cp/semantics.cc                         |  4 ++
 gcc/testsuite/g++.dg/ext/has-builtin-1.C    |  3 ++
 gcc/testsuite/g++.dg/ext/is_pointer.C       | 51 +++++++++++++++++++++
 gcc/testsuite/g++.dg/tm/pr46567.C           | 22 ++++-----
 gcc/testsuite/g++.dg/torture/20070621-1.C   |  4 +-
 gcc/testsuite/g++.dg/torture/pr57107.C      |  4 +-
 libstdc++-v3/include/bits/cpp_type_traits.h |  6 +--
 libstdc++-v3/include/bits/deque.tcc         |  6 +--
 libstdc++-v3/include/bits/stl_algobase.h    |  6 +--
 11 files changed, 86 insertions(+), 24 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/is_pointer.C
  

Comments

Ken Matsui July 10, 2023, 5:50 a.m. UTC | #1
Hi,

Here is the benchmark result for is_pointer:

https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023

Time: -62.1344%
Peak Memory Usage: -52.4281%
Total Memory Usage: -53.5889%

Sincerely,
Ken Matsui

On Sun, Jul 9, 2023 at 10:38 PM Ken Matsui <kmatsui@gcc.gnu.org> wrote:
>
> This patch implements built-in trait for std::is_pointer.
>
> gcc/cp/ChangeLog:
>
>         * cp-trait.def: Define __is_pointer.
>         * constraint.cc (diagnose_trait_expr): Handle CPTK_IS_POINTER.
>         * semantics.cc (trait_expr_value): Likewise.
>         (finish_trait_expr): Likewise.
>
> gcc/testsuite/ChangeLog:
>
>         * g++.dg/ext/has-builtin-1.C: Test existence of __is_pointer.
>         * g++.dg/ext/is_pointer.C: New test.
>         * g++.dg/tm/pr46567.C (__is_pointer): Rename to ...
>         (____is_pointer): ... this.
>         * g++.dg/torture/20070621-1.C: Likewise.
>         * g++.dg/torture/pr57107.C: Likewise.
>
> libstdc++-v3/ChangeLog:
>
>         * include/bits/cpp_type_traits.h (__is_pointer): Rename to ...
>         (____is_pointer): ... this.
>         * include/bits/deque.tcc: Use ____is_pointer instead.
>         * include/bits/stl_algobase.h: Likewise.
>
> Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
> ---
>  gcc/cp/constraint.cc                        |  3 ++
>  gcc/cp/cp-trait.def                         |  1 +
>  gcc/cp/semantics.cc                         |  4 ++
>  gcc/testsuite/g++.dg/ext/has-builtin-1.C    |  3 ++
>  gcc/testsuite/g++.dg/ext/is_pointer.C       | 51 +++++++++++++++++++++
>  gcc/testsuite/g++.dg/tm/pr46567.C           | 22 ++++-----
>  gcc/testsuite/g++.dg/torture/20070621-1.C   |  4 +-
>  gcc/testsuite/g++.dg/torture/pr57107.C      |  4 +-
>  libstdc++-v3/include/bits/cpp_type_traits.h |  6 +--
>  libstdc++-v3/include/bits/deque.tcc         |  6 +--
>  libstdc++-v3/include/bits/stl_algobase.h    |  6 +--
>  11 files changed, 86 insertions(+), 24 deletions(-)
>  create mode 100644 gcc/testsuite/g++.dg/ext/is_pointer.C
>
> diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
> index 8cf0f2d0974..30266204eb5 100644
> --- a/gcc/cp/constraint.cc
> +++ b/gcc/cp/constraint.cc
> @@ -3751,6 +3751,9 @@ diagnose_trait_expr (tree expr, tree args)
>      case CPTK_IS_UNION:
>        inform (loc, "  %qT is not a union", t1);
>        break;
> +    case CPTK_IS_POINTER:
> +      inform (loc, "  %qT is not a pointer", t1);
> +      break;
>      case CPTK_IS_AGGREGATE:
>        inform (loc, "  %qT is not an aggregate", t1);
>        break;
> diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
> index 8b7fece0cc8..b7c263e9a77 100644
> --- a/gcc/cp/cp-trait.def
> +++ b/gcc/cp/cp-trait.def
> @@ -82,6 +82,7 @@ DEFTRAIT_EXPR (IS_TRIVIALLY_ASSIGNABLE, "__is_trivially_assignable", 2)
>  DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE, "__is_trivially_constructible", -1)
>  DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
>  DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
> +DEFTRAIT_EXPR (IS_POINTER, "__is_pointer", 1)
>  DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY, "__reference_constructs_from_temporary", 2)
>  DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY, "__reference_converts_from_temporary", 2)
>  /* FIXME Added space to avoid direct usage in GCC 13.  */
> diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
> index 8fb47fd179e..68f8a4fe85b 100644
> --- a/gcc/cp/semantics.cc
> +++ b/gcc/cp/semantics.cc
> @@ -12118,6 +12118,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
>      case CPTK_IS_UNION:
>        return type_code1 == UNION_TYPE;
>
> +    case CPTK_IS_POINTER:
> +      return TYPE_PTR_P (type1);
> +
>      case CPTK_IS_ASSIGNABLE:
>        return is_xible (MODIFY_EXPR, type1, type2);
>
> @@ -12296,6 +12299,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
>      case CPTK_IS_ENUM:
>      case CPTK_IS_UNION:
>      case CPTK_IS_SAME:
> +    case CPTK_IS_POINTER:
>        break;
>
>      case CPTK_IS_LAYOUT_COMPATIBLE:
> diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> index f343e153e56..9dace5cbd48 100644
> --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
> @@ -146,3 +146,6 @@
>  #if !__has_builtin (__remove_cvref)
>  # error "__has_builtin (__remove_cvref) failed"
>  #endif
> +#if !__has_builtin (__is_pointer)
> +# error "__has_builtin (__is_pointer) failed"
> +#endif
> diff --git a/gcc/testsuite/g++.dg/ext/is_pointer.C b/gcc/testsuite/g++.dg/ext/is_pointer.C
> new file mode 100644
> index 00000000000..d6e39565950
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/ext/is_pointer.C
> @@ -0,0 +1,51 @@
> +// { dg-do compile { target c++11 } }
> +
> +#define SA(X) static_assert((X),#X)
> +
> +SA(!__is_pointer(int));
> +SA(__is_pointer(int*));
> +SA(__is_pointer(int**));
> +
> +SA(__is_pointer(const int*));
> +SA(__is_pointer(const int**));
> +SA(__is_pointer(int* const));
> +SA(__is_pointer(int** const));
> +SA(__is_pointer(int* const* const));
> +
> +SA(__is_pointer(volatile int*));
> +SA(__is_pointer(volatile int**));
> +SA(__is_pointer(int* volatile));
> +SA(__is_pointer(int** volatile));
> +SA(__is_pointer(int* volatile* volatile));
> +
> +SA(__is_pointer(const volatile int*));
> +SA(__is_pointer(const volatile int**));
> +SA(__is_pointer(const int* volatile));
> +SA(__is_pointer(volatile int* const));
> +SA(__is_pointer(int* const volatile));
> +SA(__is_pointer(const int** volatile));
> +SA(__is_pointer(volatile int** const));
> +SA(__is_pointer(int** const volatile));
> +SA(__is_pointer(int* const* const volatile));
> +SA(__is_pointer(int* volatile* const volatile));
> +SA(__is_pointer(int* const volatile* const volatile));
> +
> +SA(!__is_pointer(int&));
> +SA(!__is_pointer(const int&));
> +SA(!__is_pointer(volatile int&));
> +SA(!__is_pointer(const volatile int&));
> +
> +SA(!__is_pointer(int&&));
> +SA(!__is_pointer(const int&&));
> +SA(!__is_pointer(volatile int&&));
> +SA(!__is_pointer(const volatile int&&));
> +
> +SA(!__is_pointer(int[3]));
> +SA(!__is_pointer(const int[3]));
> +SA(!__is_pointer(volatile int[3]));
> +SA(!__is_pointer(const volatile int[3]));
> +
> +SA(!__is_pointer(int(int)));
> +SA(__is_pointer(int(*const)(int)));
> +SA(__is_pointer(int(*volatile)(int)));
> +SA(__is_pointer(int(*const volatile)(int)));
> diff --git a/gcc/testsuite/g++.dg/tm/pr46567.C b/gcc/testsuite/g++.dg/tm/pr46567.C
> index 6d791484448..0896035390e 100644
> --- a/gcc/testsuite/g++.dg/tm/pr46567.C
> +++ b/gcc/testsuite/g++.dg/tm/pr46567.C
> @@ -192,13 +192,13 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>        typedef __true_type __type;
>      };
>    template<typename _Tp>
> -    struct __is_pointer
> +    struct ____is_pointer
>      {
>        enum { __value = 0 };
>        typedef __false_type __type;
>      };
>    template<typename _Tp>
> -    struct __is_pointer<_Tp*>
> +    struct ____is_pointer<_Tp*>
>      {
>        enum { __value = 1 };
>        typedef __true_type __type;
> @@ -226,7 +226,7 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>      { };
>    template<typename _Tp>
>      struct __is_scalar
> -    : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >
> +    : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >
>      { };
>    template<typename _Tp>
>      struct __is_char
> @@ -1202,8 +1202,8 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>        typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
>        typedef typename iterator_traits<_II>::iterator_category _Category;
>        const bool __simple = (__is_pod(_ValueTypeI)
> -                     && __is_pointer<_II>::__value
> -                     && __is_pointer<_OI>::__value
> +                     && ____is_pointer<_II>::__value
> +                     && ____is_pointer<_OI>::__value
>         && __are_same<_ValueTypeI, _ValueTypeO>::__value);
>        return std::__copy_move<_IsMove, __simple,
>                        _Category>::__copy_m(__first, __last, __result);
> @@ -1294,8 +1294,8 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>        typedef typename iterator_traits<_BI2>::value_type _ValueType2;
>        typedef typename iterator_traits<_BI1>::iterator_category _Category;
>        const bool __simple = (__is_pod(_ValueType1)
> -                     && __is_pointer<_BI1>::__value
> -                     && __is_pointer<_BI2>::__value
> +                     && ____is_pointer<_BI1>::__value
> +                     && ____is_pointer<_BI2>::__value
>         && __are_same<_ValueType1, _ValueType2>::__value);
>        return std::__copy_move_backward<_IsMove, __simple,
>                                 _Category>::__copy_move_b(__first,
> @@ -1426,8 +1426,8 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>        typedef typename iterator_traits<_II1>::value_type _ValueType1;
>        typedef typename iterator_traits<_II2>::value_type _ValueType2;
>        const bool __simple = (__is_integer<_ValueType1>::__value
> -                     && __is_pointer<_II1>::__value
> -                     && __is_pointer<_II2>::__value
> +                     && ____is_pointer<_II1>::__value
> +                     && ____is_pointer<_II2>::__value
>         && __are_same<_ValueType1, _ValueType2>::__value);
>        return std::__equal<__simple>::equal(__first1, __last1, __first2);
>      }
> @@ -1515,8 +1515,8 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>   (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
>    && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
>    && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
> -  && __is_pointer<_II1>::__value
> -  && __is_pointer<_II2>::__value);
> +  && ____is_pointer<_II1>::__value
> +  && ____is_pointer<_II2>::__value);
>        return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
>            __first2, __last2);
>      }
> diff --git a/gcc/testsuite/g++.dg/torture/20070621-1.C b/gcc/testsuite/g++.dg/torture/20070621-1.C
> index d8a6a76b6b0..9ae96717e4f 100644
> --- a/gcc/testsuite/g++.dg/torture/20070621-1.C
> +++ b/gcc/testsuite/g++.dg/torture/20070621-1.C
> @@ -18,7 +18,7 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>          enum {
>    __value = 0 };
>        };
> -    template<typename _Tp>     struct __is_pointer     {
> +    template<typename _Tp>     struct ____is_pointer     {
>          enum {
>    __value = 0 };
>        };
> @@ -49,7 +49,7 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>      template<typename _II1, typename _II2>     inline bool     __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)     {
>          typedef typename iterator_traits<_II1>::value_type _ValueType1;
>          typedef typename iterator_traits<_II2>::value_type _ValueType2;
> -        const bool __simple = (__is_integer<_ValueType1>::__value                       && __is_pointer<_II1>::__value                       && __is_pointer<_II2>::__value         && __are_same<_ValueType1, _ValueType2>::__value);
> +        const bool __simple = (__is_integer<_ValueType1>::__value                       && ____is_pointer<_II1>::__value                       && ____is_pointer<_II2>::__value         && __are_same<_ValueType1, _ValueType2>::__value);
>          return std::__equal<__simple>::equal(__first1, __last1, __first2);
>        }
>      template<typename _II1, typename _II2>     inline bool     equal(_II1 __first1, _II1 __last1, _II2 __first2)     {
> diff --git a/gcc/testsuite/g++.dg/torture/pr57107.C b/gcc/testsuite/g++.dg/torture/pr57107.C
> index 4dbd32bd298..1fcf337ee58 100644
> --- a/gcc/testsuite/g++.dg/torture/pr57107.C
> +++ b/gcc/testsuite/g++.dg/torture/pr57107.C
> @@ -17,7 +17,7 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>         enum {
>             __value = 0 };
>      };
> -    template<typename _Tp>     struct __is_pointer     {
> +    template<typename _Tp>     struct ____is_pointer     {
>         enum {
>             __value = 0 };
>      };
> @@ -27,7 +27,7 @@ namespace std __attribute__ ((__visibility__ ("default"))) {
>      };
>      template<typename _Tp>     struct __is_arithmetic     : public __traitor<__is_integer<_Tp>, __is_floating<_Tp> >     {
>      };
> -    template<typename _Tp>     struct __is_scalar     : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >     {
> +    template<typename _Tp>     struct __is_scalar     : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >     {
>      };
>  }
>  namespace __gnu_cxx __attribute__ ((__visibility__ ("default"))) {
> diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h
> index 4312f32a4e0..3999898ffa6 100644
> --- a/libstdc++-v3/include/bits/cpp_type_traits.h
> +++ b/libstdc++-v3/include/bits/cpp_type_traits.h
> @@ -364,14 +364,14 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
>    // Pointer types
>    //
>    template<typename _Tp>
> -    struct __is_pointer
> +    struct ____is_pointer
>      {
>        enum { __value = 0 };
>        typedef __false_type __type;
>      };
>
>    template<typename _Tp>
> -    struct __is_pointer<_Tp*>
> +    struct ____is_pointer<_Tp*>
>      {
>        enum { __value = 1 };
>        typedef __true_type __type;
> @@ -390,7 +390,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
>    //
>    template<typename _Tp>
>      struct __is_scalar
> -    : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >
> +    : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >
>      { };
>
>    //
> diff --git a/libstdc++-v3/include/bits/deque.tcc b/libstdc++-v3/include/bits/deque.tcc
> index a212b8a6940..9f5593fac51 100644
> --- a/libstdc++-v3/include/bits/deque.tcc
> +++ b/libstdc++-v3/include/bits/deque.tcc
> @@ -1273,7 +1273,7 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
>      {
>        const bool __simple =
>         (__is_memcmp_ordered_with<_Tp1, _Tp2>::__value
> -        && __is_pointer<_Ptr>::__value
> +        && ____is_pointer<_Ptr>::__value
>  #if __cplusplus > 201703L && __cpp_lib_concepts
>          // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
>          // so __is_byte<T> could be true, but we can't use memcmp with
> @@ -1329,8 +1329,8 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
>      {
>        const bool __simple =
>         (__is_memcmp_ordered_with<_Tp1, _Tp2>::__value
> -        && __is_pointer<_Ptr1>::__value
> -        && __is_pointer<_Ptr2>::__value
> +        && ____is_pointer<_Ptr1>::__value
> +        && ____is_pointer<_Ptr2>::__value
>  #if __cplusplus > 201703L && __cpp_lib_concepts
>          // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
>          // so __is_byte<T> could be true, but we can't use memcmp with
> diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
> index dd95e94f7e9..b061c6c1185 100644
> --- a/libstdc++-v3/include/bits/stl_algobase.h
> +++ b/libstdc++-v3/include/bits/stl_algobase.h
> @@ -1214,7 +1214,7 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
>      {
>        typedef typename iterator_traits<_II1>::value_type _ValueType1;
>        const bool __simple = ((__is_integer<_ValueType1>::__value
> -                             || __is_pointer<_ValueType1>::__value)
> +                             || ____is_pointer<_ValueType1>::__value)
>                              && __memcmpable<_II1, _II2>::__value);
>        return std::__equal<__simple>::equal(__first1, __last1, __first2);
>      }
> @@ -1377,8 +1377,8 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
>        typedef typename iterator_traits<_II2>::value_type _ValueType2;
>        const bool __simple =
>         (__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
> -        && __is_pointer<_II1>::__value
> -        && __is_pointer<_II2>::__value
> +        && ____is_pointer<_II1>::__value
> +        && ____is_pointer<_II2>::__value
>  #if __cplusplus > 201703L && __cpp_lib_concepts
>          // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
>          // so __is_byte<T> could be true, but we can't use memcmp with
> --
> 2.41.0
>
  
Jonathan Wakely July 12, 2023, 10:01 a.m. UTC | #2
On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
>
> Hi,
>
> Here is the benchmark result for is_pointer:
>
> https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
>
> Time: -62.1344%
> Peak Memory Usage: -52.4281%
> Total Memory Usage: -53.5889%

Wow!

Although maybe we could have improved our std::is_pointer_v anyway, like so:

template <typename _Tp>
  inline constexpr bool is_pointer_v = false;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp*> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* const> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* volatile> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* const volatile> = true;

I'm not sure why I didn't already do that.

Could you please benchmark that? And if it is better than the current
impl using is_pointer<_Tp>::value then we should do this in the
library:

#if __has_builtin(__is_pointer)
template <typename _Tp>
  inline constexpr bool is_pointer_v = __is_pointer(_Tp);
#else
template <typename _Tp>
  inline constexpr bool is_pointer_v = false;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp*> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* const> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* volatile> = true;
template <typename _Tp>
  inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
#endif
  
Ken Matsui July 12, 2023, 8:42 p.m. UTC | #3
On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> <libstdc++@gcc.gnu.org> wrote:
> >
> > Hi,
> >
> > Here is the benchmark result for is_pointer:
> >
> > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> >
> > Time: -62.1344%
> > Peak Memory Usage: -52.4281%
> > Total Memory Usage: -53.5889%
>
> Wow!
>
> Although maybe we could have improved our std::is_pointer_v anyway, like so:
>
> template <typename _Tp>
>   inline constexpr bool is_pointer_v = false;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp*> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* const> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
>
> I'm not sure why I didn't already do that.
>
> Could you please benchmark that? And if it is better than the current
> impl using is_pointer<_Tp>::value then we should do this in the
> library:
>
> #if __has_builtin(__is_pointer)
> template <typename _Tp>
>   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> #else
> template <typename _Tp>
>   inline constexpr bool is_pointer_v = false;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp*> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* const> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> template <typename _Tp>
>   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> #endif

Hi François and Jonathan,

Thank you for your reviews! I will rename the four underscores to the
appropriate name and take a benchmark once I get home.

If I apply your change on is_pointer_v, is it better to add the
`Co-authored-by:` line in the commit?
  
Jonathan Wakely July 13, 2023, 9:21 a.m. UTC | #4
On Wed, 12 Jul 2023 at 21:42, Ken Matsui <kmatsui@cs.washington.edu> wrote:
>
> On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> >
> > On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> > <libstdc++@gcc.gnu.org> wrote:
> > >
> > > Hi,
> > >
> > > Here is the benchmark result for is_pointer:
> > >
> > > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> > >
> > > Time: -62.1344%
> > > Peak Memory Usage: -52.4281%
> > > Total Memory Usage: -53.5889%
> >
> > Wow!
> >
> > Although maybe we could have improved our std::is_pointer_v anyway, like so:
> >
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v = false;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> >
> > I'm not sure why I didn't already do that.
> >
> > Could you please benchmark that? And if it is better than the current
> > impl using is_pointer<_Tp>::value then we should do this in the
> > library:
> >
> > #if __has_builtin(__is_pointer)
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> > #else
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v = false;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > template <typename _Tp>
> >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > #endif
>
> Hi François and Jonathan,
>
> Thank you for your reviews! I will rename the four underscores to the
> appropriate name and take a benchmark once I get home.
>
> If I apply your change on is_pointer_v, is it better to add the
> `Co-authored-by:` line in the commit?

Yes, that would be the correct thing to do (although in this case the
change is small enough that I don't really care about getting credit
for it :-)
  
Ken Matsui July 13, 2023, 8:04 p.m. UTC | #5
On Thu, Jul 13, 2023 at 2:22 AM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Wed, 12 Jul 2023 at 21:42, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> >
> > On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > >
> > > On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> > > <libstdc++@gcc.gnu.org> wrote:
> > > >
> > > > Hi,
> > > >
> > > > Here is the benchmark result for is_pointer:
> > > >
> > > > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> > > >
> > > > Time: -62.1344%
> > > > Peak Memory Usage: -52.4281%
> > > > Total Memory Usage: -53.5889%
> > >
> > > Wow!
> > >
> > > Although maybe we could have improved our std::is_pointer_v anyway, like so:
> > >
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v = false;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > >
> > > I'm not sure why I didn't already do that.
> > >
> > > Could you please benchmark that? And if it is better than the current
> > > impl using is_pointer<_Tp>::value then we should do this in the
> > > library:
> > >
> > > #if __has_builtin(__is_pointer)
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> > > #else
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v = false;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > template <typename _Tp>
> > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > #endif
> >
> > Hi François and Jonathan,
> >
> > Thank you for your reviews! I will rename the four underscores to the
> > appropriate name and take a benchmark once I get home.
> >
> > If I apply your change on is_pointer_v, is it better to add the
> > `Co-authored-by:` line in the commit?
>
> Yes, that would be the correct thing to do (although in this case the
> change is small enough that I don't really care about getting credit
> for it :-)
>
Thank you! I will include it in my commit :) I see that you included
the DCO sign-off in the MAINTAINERS file. However, if a reviewer
doesn't, should I include the `Signed-off-by:` line for the reviewer
as well?
  
Jonathan Wakely July 14, 2023, 10:48 a.m. UTC | #6
On Thu, 13 Jul 2023 at 21:04, Ken Matsui <kmatsui@cs.washington.edu> wrote:
>
> On Thu, Jul 13, 2023 at 2:22 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> >
> > On Wed, 12 Jul 2023 at 21:42, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> > >
> > > On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > > >
> > > > On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> > > > <libstdc++@gcc.gnu.org> wrote:
> > > > >
> > > > > Hi,
> > > > >
> > > > > Here is the benchmark result for is_pointer:
> > > > >
> > > > > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> > > > >
> > > > > Time: -62.1344%
> > > > > Peak Memory Usage: -52.4281%
> > > > > Total Memory Usage: -53.5889%
> > > >
> > > > Wow!
> > > >
> > > > Although maybe we could have improved our std::is_pointer_v anyway, like so:
> > > >
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v = false;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > >
> > > > I'm not sure why I didn't already do that.
> > > >
> > > > Could you please benchmark that? And if it is better than the current
> > > > impl using is_pointer<_Tp>::value then we should do this in the
> > > > library:
> > > >
> > > > #if __has_builtin(__is_pointer)
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> > > > #else
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v = false;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > template <typename _Tp>
> > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > > #endif
> > >
> > > Hi François and Jonathan,
> > >
> > > Thank you for your reviews! I will rename the four underscores to the
> > > appropriate name and take a benchmark once I get home.
> > >
> > > If I apply your change on is_pointer_v, is it better to add the
> > > `Co-authored-by:` line in the commit?
> >
> > Yes, that would be the correct thing to do (although in this case the
> > change is small enough that I don't really care about getting credit
> > for it :-)
> >
> Thank you! I will include it in my commit :) I see that you included
> the DCO sign-off in the MAINTAINERS file. However, if a reviewer
> doesn't, should I include the `Signed-off-by:` line for the reviewer
> as well?

No, reviewers should not sign-off, that's for the code author. And
authors should add that themselves (or clearly state that they agree
to the DCO terms). You should not sign-off on someone else's behalf.
  
Jonathan Wakely July 14, 2023, 10:49 a.m. UTC | #7
On Fri, 14 Jul 2023 at 11:48, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Thu, 13 Jul 2023 at 21:04, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> >
> > On Thu, Jul 13, 2023 at 2:22 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > >
> > > On Wed, 12 Jul 2023 at 21:42, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> > > >
> > > > On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > > > >
> > > > > On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> > > > > <libstdc++@gcc.gnu.org> wrote:
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > Here is the benchmark result for is_pointer:
> > > > > >
> > > > > > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> > > > > >
> > > > > > Time: -62.1344%
> > > > > > Peak Memory Usage: -52.4281%
> > > > > > Total Memory Usage: -53.5889%
> > > > >
> > > > > Wow!
> > > > >
> > > > > Although maybe we could have improved our std::is_pointer_v anyway, like so:
> > > > >
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v = false;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > > >
> > > > > I'm not sure why I didn't already do that.
> > > > >
> > > > > Could you please benchmark that? And if it is better than the current
> > > > > impl using is_pointer<_Tp>::value then we should do this in the
> > > > > library:
> > > > >
> > > > > #if __has_builtin(__is_pointer)
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> > > > > #else
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v = false;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > > template <typename _Tp>
> > > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > > > #endif
> > > >
> > > > Hi François and Jonathan,
> > > >
> > > > Thank you for your reviews! I will rename the four underscores to the
> > > > appropriate name and take a benchmark once I get home.
> > > >
> > > > If I apply your change on is_pointer_v, is it better to add the
> > > > `Co-authored-by:` line in the commit?
> > >
> > > Yes, that would be the correct thing to do (although in this case the
> > > change is small enough that I don't really care about getting credit
> > > for it :-)
> > >
> > Thank you! I will include it in my commit :) I see that you included
> > the DCO sign-off in the MAINTAINERS file. However, if a reviewer
> > doesn't, should I include the `Signed-off-by:` line for the reviewer
> > as well?
>
> No, reviewers should not sign-off, that's for the code author. And
> authors should add that themselves (or clearly state that they agree
> to the DCO terms). You should not sign-off on someone else's behalf.

You can add Reviewed-by: if you want to record that information.
  
Ken Matsui July 14, 2023, 7:55 p.m. UTC | #8
On Fri, Jul 14, 2023 at 3:49 AM Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Fri, 14 Jul 2023 at 11:48, Jonathan Wakely <jwakely@redhat.com> wrote:
> >
> > On Thu, 13 Jul 2023 at 21:04, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> > >
> > > On Thu, Jul 13, 2023 at 2:22 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > > >
> > > > On Wed, 12 Jul 2023 at 21:42, Ken Matsui <kmatsui@cs.washington.edu> wrote:
> > > > >
> > > > > On Wed, Jul 12, 2023 at 3:01 AM Jonathan Wakely <jwakely@redhat.com> wrote:
> > > > > >
> > > > > > On Mon, 10 Jul 2023 at 06:51, Ken Matsui via Libstdc++
> > > > > > <libstdc++@gcc.gnu.org> wrote:
> > > > > > >
> > > > > > > Hi,
> > > > > > >
> > > > > > > Here is the benchmark result for is_pointer:
> > > > > > >
> > > > > > > https://github.com/ken-matsui/gcc-benches/blob/main/is_pointer.md#sun-jul--9-103948-pm-pdt-2023
> > > > > > >
> > > > > > > Time: -62.1344%
> > > > > > > Peak Memory Usage: -52.4281%
> > > > > > > Total Memory Usage: -53.5889%
> > > > > >
> > > > > > Wow!
> > > > > >
> > > > > > Although maybe we could have improved our std::is_pointer_v anyway, like so:
> > > > > >
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v = false;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > > > >
> > > > > > I'm not sure why I didn't already do that.
> > > > > >
> > > > > > Could you please benchmark that? And if it is better than the current
> > > > > > impl using is_pointer<_Tp>::value then we should do this in the
> > > > > > library:
> > > > > >
> > > > > > #if __has_builtin(__is_pointer)
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v = __is_pointer(_Tp);
> > > > > > #else
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v = false;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp*> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* const> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* volatile> = true;
> > > > > > template <typename _Tp>
> > > > > >   inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
> > > > > > #endif
> > > > >
> > > > > Hi François and Jonathan,
> > > > >
> > > > > Thank you for your reviews! I will rename the four underscores to the
> > > > > appropriate name and take a benchmark once I get home.
> > > > >
> > > > > If I apply your change on is_pointer_v, is it better to add the
> > > > > `Co-authored-by:` line in the commit?
> > > >
> > > > Yes, that would be the correct thing to do (although in this case the
> > > > change is small enough that I don't really care about getting credit
> > > > for it :-)
> > > >
> > > Thank you! I will include it in my commit :) I see that you included
> > > the DCO sign-off in the MAINTAINERS file. However, if a reviewer
> > > doesn't, should I include the `Signed-off-by:` line for the reviewer
> > > as well?
> >
> > No, reviewers should not sign-off, that's for the code author. And
> > authors should add that themselves (or clearly state that they agree
> > to the DCO terms). You should not sign-off on someone else's behalf.
>
> You can add Reviewed-by: if you want to record that information.
>
I see. Thank you!
  

Patch

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 8cf0f2d0974..30266204eb5 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -3751,6 +3751,9 @@  diagnose_trait_expr (tree expr, tree args)
     case CPTK_IS_UNION:
       inform (loc, "  %qT is not a union", t1);
       break;
+    case CPTK_IS_POINTER:
+      inform (loc, "  %qT is not a pointer", t1);
+      break;
     case CPTK_IS_AGGREGATE:
       inform (loc, "  %qT is not an aggregate", t1);
       break;
diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def
index 8b7fece0cc8..b7c263e9a77 100644
--- a/gcc/cp/cp-trait.def
+++ b/gcc/cp/cp-trait.def
@@ -82,6 +82,7 @@  DEFTRAIT_EXPR (IS_TRIVIALLY_ASSIGNABLE, "__is_trivially_assignable", 2)
 DEFTRAIT_EXPR (IS_TRIVIALLY_CONSTRUCTIBLE, "__is_trivially_constructible", -1)
 DEFTRAIT_EXPR (IS_TRIVIALLY_COPYABLE, "__is_trivially_copyable", 1)
 DEFTRAIT_EXPR (IS_UNION, "__is_union", 1)
+DEFTRAIT_EXPR (IS_POINTER, "__is_pointer", 1)
 DEFTRAIT_EXPR (REF_CONSTRUCTS_FROM_TEMPORARY, "__reference_constructs_from_temporary", 2)
 DEFTRAIT_EXPR (REF_CONVERTS_FROM_TEMPORARY, "__reference_converts_from_temporary", 2)
 /* FIXME Added space to avoid direct usage in GCC 13.  */
diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc
index 8fb47fd179e..68f8a4fe85b 100644
--- a/gcc/cp/semantics.cc
+++ b/gcc/cp/semantics.cc
@@ -12118,6 +12118,9 @@  trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_UNION:
       return type_code1 == UNION_TYPE;
 
+    case CPTK_IS_POINTER:
+      return TYPE_PTR_P (type1);
+
     case CPTK_IS_ASSIGNABLE:
       return is_xible (MODIFY_EXPR, type1, type2);
 
@@ -12296,6 +12299,7 @@  finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2)
     case CPTK_IS_ENUM:
     case CPTK_IS_UNION:
     case CPTK_IS_SAME:
+    case CPTK_IS_POINTER:
       break;
 
     case CPTK_IS_LAYOUT_COMPATIBLE:
diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
index f343e153e56..9dace5cbd48 100644
--- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C
+++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C
@@ -146,3 +146,6 @@ 
 #if !__has_builtin (__remove_cvref)
 # error "__has_builtin (__remove_cvref) failed"
 #endif
+#if !__has_builtin (__is_pointer)
+# error "__has_builtin (__is_pointer) failed"
+#endif
diff --git a/gcc/testsuite/g++.dg/ext/is_pointer.C b/gcc/testsuite/g++.dg/ext/is_pointer.C
new file mode 100644
index 00000000000..d6e39565950
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/is_pointer.C
@@ -0,0 +1,51 @@ 
+// { dg-do compile { target c++11 } }
+
+#define SA(X) static_assert((X),#X)
+
+SA(!__is_pointer(int));
+SA(__is_pointer(int*));
+SA(__is_pointer(int**));
+
+SA(__is_pointer(const int*));
+SA(__is_pointer(const int**));
+SA(__is_pointer(int* const));
+SA(__is_pointer(int** const));
+SA(__is_pointer(int* const* const));
+
+SA(__is_pointer(volatile int*));
+SA(__is_pointer(volatile int**));
+SA(__is_pointer(int* volatile));
+SA(__is_pointer(int** volatile));
+SA(__is_pointer(int* volatile* volatile));
+
+SA(__is_pointer(const volatile int*));
+SA(__is_pointer(const volatile int**));
+SA(__is_pointer(const int* volatile));
+SA(__is_pointer(volatile int* const));
+SA(__is_pointer(int* const volatile));
+SA(__is_pointer(const int** volatile));
+SA(__is_pointer(volatile int** const));
+SA(__is_pointer(int** const volatile));
+SA(__is_pointer(int* const* const volatile));
+SA(__is_pointer(int* volatile* const volatile));
+SA(__is_pointer(int* const volatile* const volatile));
+
+SA(!__is_pointer(int&));
+SA(!__is_pointer(const int&));
+SA(!__is_pointer(volatile int&));
+SA(!__is_pointer(const volatile int&));
+
+SA(!__is_pointer(int&&));
+SA(!__is_pointer(const int&&));
+SA(!__is_pointer(volatile int&&));
+SA(!__is_pointer(const volatile int&&));
+
+SA(!__is_pointer(int[3]));
+SA(!__is_pointer(const int[3]));
+SA(!__is_pointer(volatile int[3]));
+SA(!__is_pointer(const volatile int[3]));
+
+SA(!__is_pointer(int(int)));
+SA(__is_pointer(int(*const)(int)));
+SA(__is_pointer(int(*volatile)(int)));
+SA(__is_pointer(int(*const volatile)(int)));
diff --git a/gcc/testsuite/g++.dg/tm/pr46567.C b/gcc/testsuite/g++.dg/tm/pr46567.C
index 6d791484448..0896035390e 100644
--- a/gcc/testsuite/g++.dg/tm/pr46567.C
+++ b/gcc/testsuite/g++.dg/tm/pr46567.C
@@ -192,13 +192,13 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
       typedef __true_type __type;
     };
   template<typename _Tp>
-    struct __is_pointer
+    struct ____is_pointer
     {
       enum { __value = 0 };
       typedef __false_type __type;
     };
   template<typename _Tp>
-    struct __is_pointer<_Tp*>
+    struct ____is_pointer<_Tp*>
     {
       enum { __value = 1 };
       typedef __true_type __type;
@@ -226,7 +226,7 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
     { };
   template<typename _Tp>
     struct __is_scalar
-    : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >
+    : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >
     { };
   template<typename _Tp>
     struct __is_char
@@ -1202,8 +1202,8 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
       typedef typename iterator_traits<_OI>::value_type _ValueTypeO;
       typedef typename iterator_traits<_II>::iterator_category _Category;
       const bool __simple = (__is_pod(_ValueTypeI)
-		      && __is_pointer<_II>::__value
-		      && __is_pointer<_OI>::__value
+		      && ____is_pointer<_II>::__value
+		      && ____is_pointer<_OI>::__value
 	&& __are_same<_ValueTypeI, _ValueTypeO>::__value);
       return std::__copy_move<_IsMove, __simple,
 		       _Category>::__copy_m(__first, __last, __result);
@@ -1294,8 +1294,8 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
       typedef typename iterator_traits<_BI2>::value_type _ValueType2;
       typedef typename iterator_traits<_BI1>::iterator_category _Category;
       const bool __simple = (__is_pod(_ValueType1)
-		      && __is_pointer<_BI1>::__value
-		      && __is_pointer<_BI2>::__value
+		      && ____is_pointer<_BI1>::__value
+		      && ____is_pointer<_BI2>::__value
 	&& __are_same<_ValueType1, _ValueType2>::__value);
       return std::__copy_move_backward<_IsMove, __simple,
 				_Category>::__copy_move_b(__first,
@@ -1426,8 +1426,8 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
       typedef typename iterator_traits<_II1>::value_type _ValueType1;
       typedef typename iterator_traits<_II2>::value_type _ValueType2;
       const bool __simple = (__is_integer<_ValueType1>::__value
-		      && __is_pointer<_II1>::__value
-		      && __is_pointer<_II2>::__value
+		      && ____is_pointer<_II1>::__value
+		      && ____is_pointer<_II2>::__value
 	&& __are_same<_ValueType1, _ValueType2>::__value);
       return std::__equal<__simple>::equal(__first1, __last1, __first2);
     }
@@ -1515,8 +1515,8 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
  (__is_byte<_ValueType1>::__value && __is_byte<_ValueType2>::__value
   && !__gnu_cxx::__numeric_traits<_ValueType1>::__is_signed
   && !__gnu_cxx::__numeric_traits<_ValueType2>::__is_signed
-  && __is_pointer<_II1>::__value
-  && __is_pointer<_II2>::__value);
+  && ____is_pointer<_II1>::__value
+  && ____is_pointer<_II2>::__value);
       return std::__lexicographical_compare<__simple>::__lc(__first1, __last1,
 	   __first2, __last2);
     }
diff --git a/gcc/testsuite/g++.dg/torture/20070621-1.C b/gcc/testsuite/g++.dg/torture/20070621-1.C
index d8a6a76b6b0..9ae96717e4f 100644
--- a/gcc/testsuite/g++.dg/torture/20070621-1.C
+++ b/gcc/testsuite/g++.dg/torture/20070621-1.C
@@ -18,7 +18,7 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
         enum {
   __value = 0 };
       };
-    template<typename _Tp>     struct __is_pointer     {
+    template<typename _Tp>     struct ____is_pointer     {
         enum {
   __value = 0 };
       };
@@ -49,7 +49,7 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
     template<typename _II1, typename _II2>     inline bool     __equal_aux(_II1 __first1, _II1 __last1, _II2 __first2)     {
         typedef typename iterator_traits<_II1>::value_type _ValueType1;
         typedef typename iterator_traits<_II2>::value_type _ValueType2;
-        const bool __simple = (__is_integer<_ValueType1>::__value                       && __is_pointer<_II1>::__value                       && __is_pointer<_II2>::__value         && __are_same<_ValueType1, _ValueType2>::__value);
+        const bool __simple = (__is_integer<_ValueType1>::__value                       && ____is_pointer<_II1>::__value                       && ____is_pointer<_II2>::__value         && __are_same<_ValueType1, _ValueType2>::__value);
         return std::__equal<__simple>::equal(__first1, __last1, __first2);
       }
     template<typename _II1, typename _II2>     inline bool     equal(_II1 __first1, _II1 __last1, _II2 __first2)     {
diff --git a/gcc/testsuite/g++.dg/torture/pr57107.C b/gcc/testsuite/g++.dg/torture/pr57107.C
index 4dbd32bd298..1fcf337ee58 100644
--- a/gcc/testsuite/g++.dg/torture/pr57107.C
+++ b/gcc/testsuite/g++.dg/torture/pr57107.C
@@ -17,7 +17,7 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
 	enum {
 	    __value = 0 };
     };
-    template<typename _Tp>     struct __is_pointer     {
+    template<typename _Tp>     struct ____is_pointer     {
 	enum {
 	    __value = 0 };
     };
@@ -27,7 +27,7 @@  namespace std __attribute__ ((__visibility__ ("default"))) {
     };
     template<typename _Tp>     struct __is_arithmetic     : public __traitor<__is_integer<_Tp>, __is_floating<_Tp> >     {
     };
-    template<typename _Tp>     struct __is_scalar     : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >     {
+    template<typename _Tp>     struct __is_scalar     : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >     {
     };
 }
 namespace __gnu_cxx __attribute__ ((__visibility__ ("default"))) {
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h
index 4312f32a4e0..3999898ffa6 100644
--- a/libstdc++-v3/include/bits/cpp_type_traits.h
+++ b/libstdc++-v3/include/bits/cpp_type_traits.h
@@ -364,14 +364,14 @@  __INT_N(__GLIBCXX_TYPE_INT_N_3)
   // Pointer types
   //
   template<typename _Tp>
-    struct __is_pointer
+    struct ____is_pointer
     {
       enum { __value = 0 };
       typedef __false_type __type;
     };
 
   template<typename _Tp>
-    struct __is_pointer<_Tp*>
+    struct ____is_pointer<_Tp*>
     {
       enum { __value = 1 };
       typedef __true_type __type;
@@ -390,7 +390,7 @@  __INT_N(__GLIBCXX_TYPE_INT_N_3)
   // 
   template<typename _Tp>
     struct __is_scalar
-    : public __traitor<__is_arithmetic<_Tp>, __is_pointer<_Tp> >
+    : public __traitor<__is_arithmetic<_Tp>, ____is_pointer<_Tp> >
     { };
 
   //
diff --git a/libstdc++-v3/include/bits/deque.tcc b/libstdc++-v3/include/bits/deque.tcc
index a212b8a6940..9f5593fac51 100644
--- a/libstdc++-v3/include/bits/deque.tcc
+++ b/libstdc++-v3/include/bits/deque.tcc
@@ -1273,7 +1273,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       const bool __simple =
 	(__is_memcmp_ordered_with<_Tp1, _Tp2>::__value
-	 && __is_pointer<_Ptr>::__value
+	 && ____is_pointer<_Ptr>::__value
 #if __cplusplus > 201703L && __cpp_lib_concepts
 	 // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
 	 // so __is_byte<T> could be true, but we can't use memcmp with
@@ -1329,8 +1329,8 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       const bool __simple =
 	(__is_memcmp_ordered_with<_Tp1, _Tp2>::__value
-	 && __is_pointer<_Ptr1>::__value
-	 && __is_pointer<_Ptr2>::__value
+	 && ____is_pointer<_Ptr1>::__value
+	 && ____is_pointer<_Ptr2>::__value
 #if __cplusplus > 201703L && __cpp_lib_concepts
 	 // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
 	 // so __is_byte<T> could be true, but we can't use memcmp with
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index dd95e94f7e9..b061c6c1185 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -1214,7 +1214,7 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       typedef typename iterator_traits<_II1>::value_type _ValueType1;
       const bool __simple = ((__is_integer<_ValueType1>::__value
-			      || __is_pointer<_ValueType1>::__value)
+			      || ____is_pointer<_ValueType1>::__value)
 			     && __memcmpable<_II1, _II2>::__value);
       return std::__equal<__simple>::equal(__first1, __last1, __first2);
     }
@@ -1377,8 +1377,8 @@  _GLIBCXX_END_NAMESPACE_CONTAINER
       typedef typename iterator_traits<_II2>::value_type _ValueType2;
       const bool __simple =
 	(__is_memcmp_ordered_with<_ValueType1, _ValueType2>::__value
-	 && __is_pointer<_II1>::__value
-	 && __is_pointer<_II2>::__value
+	 && ____is_pointer<_II1>::__value
+	 && ____is_pointer<_II2>::__value
 #if __cplusplus > 201703L && __cpp_lib_concepts
 	 // For C++20 iterator_traits<volatile T*>::value_type is non-volatile
 	 // so __is_byte<T> could be true, but we can't use memcmp with