From: Jonathan Wakely <jwakely@redhat.com>
To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org
Subject: [committed] libstdc++: Skip tag dispatching for _S_relocate in C++17
Date: Tue, 30 Nov 2021 20:11:45 +0000 [thread overview]
Message-ID: <20211130201145.107767-1-jwakely@redhat.com> (raw)
Tested x86_64-linux, pushed to trunk.
In C++17 mode all callers of _S_relocate have already done:
if constexpr (_S_use_relocate())
so we don't need to repeat that check and use tag dispatching to avoid
ill-formed instantiations.
libstdc++-v3/ChangeLog:
* include/bits/stl_vector.h (vector::_S_do_relocate): Remove
C++20 constexpr specifier.
(vector::_S_relocate) [__cpp_if_constexpr]: Call __relocate_a
directly without tag dispatching.
---
libstdc++-v3/include/bits/stl_vector.h | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/bits/stl_vector.h b/libstdc++-v3/include/bits/stl_vector.h
index 4587757637e..36b2cff3d78 100644
--- a/libstdc++-v3/include/bits/stl_vector.h
+++ b/libstdc++-v3/include/bits/stl_vector.h
@@ -481,14 +481,14 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
return _S_nothrow_relocate(__is_move_insertable<_Tp_alloc_type>{});
}
- static _GLIBCXX20_CONSTEXPR pointer
+ static pointer
_S_do_relocate(pointer __first, pointer __last, pointer __result,
_Tp_alloc_type& __alloc, true_type) noexcept
{
return std::__relocate_a(__first, __last, __result, __alloc);
}
- static _GLIBCXX20_CONSTEXPR pointer
+ static pointer
_S_do_relocate(pointer, pointer, pointer __result,
_Tp_alloc_type&, false_type) noexcept
{ return __result; }
@@ -497,8 +497,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
_S_relocate(pointer __first, pointer __last, pointer __result,
_Tp_alloc_type& __alloc) noexcept
{
+#if __cpp_if_constexpr
+ // All callers have already checked _S_use_relocate() so just do it.
+ return std::__relocate_a(__first, __last, __result, __alloc);
+#else
using __do_it = __bool_constant<_S_use_relocate()>;
return _S_do_relocate(__first, __last, __result, __alloc, __do_it{});
+#endif
}
#endif // C++11
--
2.31.1
reply other threads:[~2021-11-30 20:11 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20211130201145.107767-1-jwakely@redhat.com \
--to=jwakely@redhat.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=libstdc++@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).