[Bug libstdc++/100900] New: error: missing 'typename' prior to dependent type name in <ranges> elements_view

[Bug libstdc++/100900] New: error: missing 'typename' prior to dependent type name in <ranges> elements_view

[avi@cloudius-systems.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

            Bug ID: 100900
           Summary: error: missing 'typename' prior to dependent type name
                    in <ranges> elements_view
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: avi@cloudius-systems.com
  Target Milestone: ---

clang++ complains:

/usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11/ranges:3392:19:
error: missing 'typename' prior to dependent type name
'iterator_traits<iterator_t<_Base>>::iterator_category'
            using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category;

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

康桓瑋 <hewillk at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hewillk at gmail dot com

--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> ---
(In reply to Avi Kivity from comment #0)
> clang++ complains:
> 
> /usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11/ranges:3392:
> 19: error: missing 'typename' prior to dependent type name
> 'iterator_traits<iterator_t<_Base>>::iterator_category'
>             using _Cat =
> iterator_traits<iterator_t<_Base>>::iterator_category;

Clang doesn't fully support the C++20 language features that libstdc++ uses in
its implementation (Down with typename!).
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p0634r3.html

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-06-04

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Yes, this is a gap in clang's C++20 implementation, so we should work around it
in libstdc++.

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
                 CC|                            |ppalka at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[avi@cloudius-systems.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

--- Comment #3 from Avi Kivity <avi@cloudius-systems.com> ---
Note, I posted a patch for this to gcc-patches, to save you the effort of
typing those 9 letters.

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|ppalka at gcc dot gnu.org          |unassigned at gcc dot gnu.org

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
(In reply to Avi Kivity from comment #3)
> Note, I posted a patch for this to gcc-patches, to save you the effort of
> typing those 9 letters.

Ah thanks, I missed that :)

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:5e2e15f212e2458a1258b8c856895c755460bc6b

commit r12-1262-g5e2e15f212e2458a1258b8c856895c755460bc6b
Author: Avi Kivity <avi@scylladb.com>
Date:   Mon Jun 7 11:19:05 2021 -0400

    libstdc++: add missing typename for dependent type in ranges::elements_view
[PR100900]

    Clang complains about the missing typename. I believe it's not required
    in a more complete implementation of C++, but it's nicer to support
    less complete implementations.

            PR libstdc++/100900

    libstdc++-v3/ChangeLog:

            * include/std/ranges (elements_view::__iter_cat::_S_iter_cat):
            Add missing typename.

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:23fa1e7eab7680ae0488b4c8802b0bcd8f78425d

commit r11-8519-g23fa1e7eab7680ae0488b4c8802b0bcd8f78425d
Author: Avi Kivity <avi@scylladb.com>
Date:   Mon Jun 7 11:19:05 2021 -0400

    libstdc++: add missing typename for dependent type in ranges::elements_view
[PR100900]

    Clang complains about the missing typename. I believe it's not required
    in a more complete implementation of C++, but it's nicer to support
    less complete implementations.

            PR libstdc++/100900

    libstdc++-v3/ChangeLog:

            * include/std/ranges (elements_view::__iter_cat::_S_iter_cat):
            Add missing typename.

    (cherry picked from commit 5e2e15f212e2458a1258b8c856895c755460bc6b)

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.2
             Status|ASSIGNED                    |RESOLVED
           Keywords|                            |build
         Resolution|---                         |FIXED

--- Comment #7 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Patch pushed to trunk and the 11 branch, thanks!

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[avi@cloudius-systems.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

--- Comment #8 from Avi Kivity <avi@cloudius-systems.com> ---
I see you added the changelog entry. I'll be sure to do that next time I post a
patch.

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[ldv at sourceware dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Dmitry V. Levin <ldv at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ldv at sourceware dot org

--- Comment #9 from Dmitry V. Levin <ldv at sourceware dot org> ---
Since PR95983 fix was backported to gcc-10 (by commit
1cb39945993c89746b0347746bd1267de85cbc42), please backport this follow-up fix
to gcc-10, too.

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:e9fbf0f9d621213ea16713b595feb88b789a8858

commit r10-9969-ge9fbf0f9d621213ea16713b595feb88b789a8858
Author: Avi Kivity <avi@scylladb.com>
Date:   Mon Jun 7 11:19:05 2021 -0400

    libstdc++: add missing typename for dependent type in ranges::elements_view
[PR100900]

    Clang complains about the missing typename. I believe it's not required
    in a more complete implementation of C++, but it's nicer to support
    less complete implementations.

            PR libstdc++/100900

    libstdc++-v3/ChangeLog:

            * include/std/ranges (elements_view::__iter_cat::_S_iter_cat):
            Add missing typename.

    (cherry picked from commit 5e2e15f212e2458a1258b8c856895c755460bc6b)

[Bug libstdc++/100900] error: missing 'typename' prior to dependent type name in <ranges> elements_view

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100900

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.2                        |10.4

--- Comment #11 from Patrick Palka <ppalka at gcc dot gnu.org> ---
(In reply to Dmitry V. Levin from comment #9)
> Since PR95983 fix was backported to gcc-10 (by commit
> 1cb39945993c89746b0347746bd1267de85cbc42), please backport this follow-up
> fix to gcc-10, too.

done