From: "Daniel Krügler" <daniel.kruegler@gmail.com>
To: Jonathan Wakely <jwakely@redhat.com>
Cc: "François Dumont" <frs.dumont@gmail.com>,
"libstdc++@gcc.gnu.org" <libstdc++@gcc.gnu.org>,
gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: PR 90409 Deque fiil/copy/move/copy_backward/move_backward/equal overloads
Date: Thu, 01 Aug 2019 10:36:00 -0000 [thread overview]
Message-ID: <CAGNvRgBsRonOWSwYFibyj7Dq-QCf+6EfC7sm5OcfU_AzbkUzLw@mail.gmail.com> (raw)
In-Reply-To: <20190801095726.GA28280@redhat.com>
Am Do., 1. Aug. 2019 um 11:57 Uhr schrieb Jonathan Wakely <jwakely@redhat.com>:
>
> More comments inline below ...
[..]
>
> >François
> >
> >On 6/19/19 7:32 PM, François Dumont wrote:
> >>I wanted to implement Debug overloads for those already existing
> >>overloads but then realized that those algos could be generalized.
> >>This way we will benefit from the memmove replacement when operating
> >>with C array or std::array or std::vector iterators.
> >>
> >>I might do the same for lexicographical_compare one day.
> >>
> >>The ChangeLog below is quite huge so I attached it. I wonder if I
> >>could use deque::iterator and deque::const_iterator in place of the
> >>_Deque_iterator<> to reduce it ?
> >>
> >>Tested under Linux x86_64 normal and debug modes, ok to commit ?
> >>
> >>François
> >>
> >
>
> >diff --git a/libstdc++-v3/include/bits/deque.tcc b/libstdc++-v3/include/bits/deque.tcc
> >index 3f77b4f079c..9db869fb666 100644
> >--- a/libstdc++-v3/include/bits/deque.tcc
> >+++ b/libstdc++-v3/include/bits/deque.tcc
> >@@ -967,155 +967,507 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
> > this->_M_impl._M_finish._M_set_node(__new_nstart + __old_num_nodes - 1);
> > }
> >
[..]
>
> And anyway, isn't _Deque_iterator<T, T&, T*>::_Self just the same type as
> _Deque_iterator<T, T&, T*> ? It should be something like:
>
> typedef typename _GLIBCXX_STD_C::_Deque_iterator<_Tp, _Tp&, _Tp*> _Iter;
>
> >+ template<typename _II, typename _Tp>
> >+ typename enable_if<
> >+ is_same<typename std::iterator_traits<_II>::iterator_category,
> >+ std::random_access_iterator_tag>::value,
>
> Use is_base_of<random_access_iterator_tag, ...::iterator_category> so
> it works for types derived from random_access_iterator_tag too.
Interesting. Traditional type tag dispatching approaches (as function
parameters) do have more in a manner that would be equivalent to an
implicit conversion (Being used as "by-value-parameters"), so I'm
wondering whether this should not instead refer to is_convertible? I
also found examples where this trait is currently used in <stl_algo.h>
such as
static_assert(
__or_<is_convertible<__pop_cat, forward_iterator_tag>,
is_convertible<__samp_cat, random_access_iterator_tag>>::value,
"output range must use a RandomAccessIterator when input range"
" does not meet the ForwardIterator requirements");
Should possibly this trait be preferred?
- Daniel
next prev parent reply other threads:[~2019-08-01 10:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 17:32 François Dumont
2019-06-20 8:38 ` Morwenn Ed
2019-06-21 4:43 ` François Dumont
2019-07-16 17:20 ` François Dumont
2019-07-26 9:13 ` PR 90409 " François Dumont
2019-08-01 9:57 ` Jonathan Wakely
2019-08-01 10:36 ` Daniel Krügler [this message]
2019-08-01 11:01 ` Jonathan Wakely
2019-08-01 11:31 ` Daniel Krügler
2019-08-01 12:52 ` Jonathan Wakely
2019-08-01 12:53 ` Jonathan Wakely
2019-08-21 21:18 ` François Dumont
2019-08-26 20:31 ` François Dumont
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=CAGNvRgBsRonOWSwYFibyj7Dq-QCf+6EfC7sm5OcfU_AzbkUzLw@mail.gmail.com \
--to=daniel.kruegler@gmail.com \
--cc=frs.dumont@gmail.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=jwakely@redhat.com \
--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).