From: Ken Matsui <kmatsui@cs.washington.edu>
To: Jonathan Wakely <jwakely.gcc@gmail.com>
Cc: gcc-patches <gcc-patches@gcc.gnu.org>,
Patrick Palka <ppalka@redhat.com>,
"libstdc++" <libstdc++@gcc.gnu.org>
Subject: Re: [PATCH] libstdc++: use new built-in trait __remove_pointer
Date: Mon, 20 Mar 2023 01:07:54 -0700 [thread overview]
Message-ID: <CAML+3pUXydMXzgmo8AvrBf6G9Ah=O_B8pq8kmo1hvA_rCt+DTw@mail.gmail.com> (raw)
In-Reply-To: <CAH6eHdTPb9K9S5wjmF-soAu0aHt=XxsSSS959U-FahWSduMyjQ@mail.gmail.com>
Ooh... Thank you for pointing that out!
> The helper doesn't need to be defined for the case where we don't use it.
I thought that macroing them out leads to compiler errors since users
are possibly using those helpers. But do we not have to care about
that?
---
libstdc++-v3/ChangeLog:
* include/std/type_traits (remove_pointer): Use __remove_pointer built-in trait.
---
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index 2bd607a8b8f..cba98091aad 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -2025,17 +2025,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp, typename>
struct __remove_pointer_helper
- { typedef _Tp type; };
+ { using type = _Tp; };
template<typename _Tp, typename _Up>
struct __remove_pointer_helper<_Tp, _Up*>
- { typedef _Up type; };
+ { using type = _Up; };
/// remove_pointer
+#if __has_builtin(__remove_pointer)
+ template<typename _Tp>
+ struct remove_pointer
+ { using type = __remove_pointer(_Tp); };
+#else
template<typename _Tp>
struct remove_pointer
: public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
{ };
+#endif
template<typename _Tp, typename = void>
struct __add_pointer_helper
On Mon, Mar 20, 2023 at 12:57 AM Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>
>
>
> On Mon, 20 Mar 2023, 07:32 Ken Matsui via Libstdc++, <libstdc++@gcc.gnu.org> wrote:
>>
>> CCing libstdc++@gcc.gnu.org.
>>
>> On Sun, Mar 19, 2023 at 7:53 PM Ken Matsui <kmatsui@cs.washington.edu> wrote:
>> >
>> > libstdc++-v3/ChangeLog:
>> >
>> > * include/std/type_traits (is_reference): Use __remove_pointer built-in trait.
>
>
> The changelog entry says is_reference but the patch is for remove_pointer.
>
>
>> >
>> > ---
>> > diff --git a/libstdc++-v3/include/std/type_traits
>> > b/libstdc++-v3/include/std/type_traits
>> > index 2bd607a8b8f..cba98091aad 100644
>> > --- a/libstdc++-v3/include/std/type_traits
>> > +++ b/libstdc++-v3/include/std/type_traits
>> > @@ -2025,17 +2025,23 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>> >
>> > template<typename _Tp, typename>
>> > struct __remove_pointer_helper
>> > - { typedef _Tp type; };
>> > + { using type = _Tp; };
>> >
>> > template<typename _Tp, typename _Up>
>> > struct __remove_pointer_helper<_Tp, _Up*>
>> > - { typedef _Up type; };
>> > + { using type = _Up; };
>
>
> The helper doesn't need to be defined for the case where we don't use it.
>
>
>> >
>> > /// remove_pointer
>> > +#if __has_builtin(__remove_pointer)
>> > + template<typename _Tp>
>> > + struct remove_pointer
>> > + { using type = __remove_pointer(_Tp); };
>> > +#else
>> > template<typename _Tp>
>> > struct remove_pointer
>> > : public __remove_pointer_helper<_Tp, __remove_cv_t<_Tp>>
>> > { };
>> > +#endif
>> >
>> > template<typename _Tp, typename = void>
>> > struct __add_pointer_helper
next prev parent reply other threads:[~2023-03-20 8:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-20 2:53 Ken Matsui
2023-03-20 7:31 ` Ken Matsui
2023-03-20 7:57 ` Jonathan Wakely
2023-03-20 8:07 ` Ken Matsui [this message]
2023-03-20 9:11 ` Jonathan Wakely
2023-03-20 13:26 ` Ken Matsui
2023-03-20 22:24 ` Ken Matsui
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