We raised the possibility that attendees (or anyone, really) could compile their own codebases with my implementation of P1144 and/or with Corentin's implementation of P2786, and see how they compare in terms of ergonomics. Both implementations are forks of the (Clang + libc++) monorepo.Instructions for building the P1144 compiler are here:Besides the headline- Please compile your codebase with this compiler+library combo and report the results!I have several subordinate requests:- Please, if you know how to make this more convenient (e.g. for users of VS Code with Docker), give me teh codez!- Please tell me how to build the P2786 reference implementation!- Please contact me if you're interested in a short-term contract to add P1144 support to GCC and/or libstdc++!Thanks,ArthurOn Wed, Apr 10, 2024 at 3:53 PM Michael Wong via SG14 <sg14@lists.isocpp.org> wrote:_______________________________________________On Tue, Apr 9, 2024 at 4:23 PM Michael Wong <fraggamuffin@gmail.com> wrote:Hi, this SG14 meeting will focus on Finance/Low Latency
Michael Wong is inviting you to a scheduled Zoom meeting.
Topic: SG14 monthly
Time: 2nd Wednesdays 02:00 PM Eastern Time (US and Canada)
Every month on the Second Wed,
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Agenda:
1. Opening and introduction
ISO Code of Conduct
<
https://isotc.iso.org/livelink/livelink?func=ll&objId=20882226&objAction=Open&nexturl=%2Flivelink%2Flivelink%3Ffunc%3Dll%26objId%3D20158641%26objAction%3Dbrowse%26viewType%3D1
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ISO patent policy.
https://isotc.iso.org/livelink/livelink/fetch/2000/2122/3770791/Common_Policy.htm?nodeid=6344764&vernum=-2
IEC Code of Conduct:
https://www.iec.ch/basecamp/iec-code-conduct-technical-work
WG21 Code of Conduct:
https://isocpp.org/std/standing-documents/sd-4-wg21-practices-and-procedures
1.1 Roll call of participantsAndre Kostur, Andrew Lumsdaine, Arthur ODWyer, Ben Sherman, Cryan St. Amour, Gianluca, Delfino, Jake Favold, Josh Gebara, Lauri Vasama, Matthew Butler, Phil Ratzloff, Ronen Friedman, Adarsh, Michael Wong, Jens Maurer, Alisdaire Meredith
1.2 Adopt agenda
1.3 Approve minutes from the previous meeting, and approve publishing
previously approved minutes to ISOCPP.org
1.4 Action items from previous meetings
2. Main issues (125 min)
2.1 General logistics
2024 planning
C++23 and C++26 statusTokyo F2FContracts and Microsoft feedbacksP1144 on trivially relocatableMay 15th Mailing deadline
- 2024-06-24 to 29: St. Louis, MO, USA; Bill Seymour
- 2024-11-18 to 23: Wrocław, Poland; Nokia
C++26 Deadlines
Future and past meeting plans
* Jan 10, 2024 02:00 PM ET: Games DONE
* Feb 14, 2024 02:00 PM ET: Embedded DONE
* Mar 13, 2024 02:00 PM ET: Cancelled due to Tokyo 3-18-23
* Apr 10, 2024 02:00 PM ET: Finance
* May 8, 2024 02:00 PM ET: Games/ P3160 assigned to SG14 to discuss
* June 12, 2024 02:00 PM ET: Embedded; St.louis 6-24-29
* July 10, 2024 02:00 PM ET: Finance
* Aug 14, 2024 02:00 PM ET: Games
* Sep 11, 2024 02:00 PM ET: CPPCON Sept 15-20 so cancelled
* Oct 9, 2024 02:00 PM ET: Embedded
* Nov 13, 2024 02:00 PM ET: Cancelled Wroclaw F2F
* Dec 11, 2024 02:00 PM ET: Finance
2.2 Paper reviews
Embedded:
* P3132 Accept attributes with user-defined prefixes
* P3134 Attribute [[asserts_rvo]]
Deterministic Exception for Embedded by James Renwick
https://www.pure.ed.ac.uk/ws/portalfiles/portal/78829292/low_cost_deterministic_C_exceptions_for_embedded_systems.pdf
Freestanding Updates
Games paper review
Arthur's suggestions:
(1) I put in the Slack channel
<https://cpplang.slack.com/archives/C3TK2M6HH/p1703947057425609> a while
ago Clang PR #76596 <https://github.com/llvm/llvm-project/pull/76596>, from
one Max Winkler, apparently in game dev. I don't think the PR stands much
chance of getting merged into Clang; but it might still be of interest to
SG14 folks. The issue description is very long and somewhat detailed, and
then there's more discussion/debate in the comments
<https://github.com/llvm/llvm-project/pull/76596#issuecomment-1872601156>.
(I'd actually be interested in talking to Max, but he doesn't publish his
email address on GitHub and I guess that might be on purpose.)
(2) LEWG will be seeing my P3055 "Relax wording to permit relocation
optimizations in the STL"
<https://quuxplusone.github.io/draft/d3055-relocation.html> in a telecon on
February 20th. (Related blog post.
<https://quuxplusone.github.io/blog/2024/01/02/bsl-vector-erase/>) Might
be interesting to folks who do EASTL-style containers. I'd be interested in
early feedback and/or telecon attendance.
Discussion on Embedded:
Paul's suggestions
The next meeting would then be Embedded and I would be interested in
knowing if people think a module std.freestanding is worth pursuing.
In that context I'd like to get some feedback perhaps already for the
upcoming meeting, if people have started using modules, and if so if it has
brought the promised expectations or if you are holding back if you see any
relevance in modules.
Review latest mailings:
P2532 Removing exception_ptr from the receivers concept
Based on the last meeting and the discussions here.
P2544 C++ Exceptions are becoming more and more problematic
We might want to chime in here.
/Paul
P. S. P2327 de-deprecating volatile received a "consensus" straw poll.
Discussion on Low Latency/Finance topics
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p1839r4.pdfWho is in FInance
Please will someone stand to be Finance SIG chair?
Bryan St. Amour (Maystreet) ultra low latency, market feed, data handler, high frequency, banks
-data capture side, network, packets, 0 allocation, without dropping to a lower language
-cant do heap allocation, runtime eh is not fine
Nathan Owen(Maystreet) - embedded but now Finace
Ben Sherman (Chicago Trading) - market maker
-compile time evaluation, value semantics, type manip,
-strggle in type with iteration, transformation in constexpr values
Jake Fevold (Bloomberg) - finance media company
-contracts
-safety
Alisdair Meredith
-allocators, control memory location, low latency
Gianluca Delfino (maystreet)
- MS before, trivially relocatable object, reinterpret cast, in-place vectors to know allocation, cache locality
-security (not on networks), memory/resource/dangling type of safety, allocation, memory, locality, network facility, lifetimes
Josh Gebara (Bloomberg) - allocators, safety
Is there any grassroot movement to Rust? No from Maystreet. Concerned the RUST hype vs C++ viability and investment. May be offer a C++ solutions to memory safe RUST
Discussion about Games topics:
P2388R1 - Minimum Contract Support: either Ignore or Check_and_abort
<http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2388r1.html>
2.2.1 any other proposal for reviews?
SG14/SG19 features/issues/defects:
https://docs.google.com/spreadsheets/d/1JnUJBO72QVURttkKr7gn0_WjP--P0vAne8JBfzbRiy0/edit#gid=0
2.3 Domain-specific discussions
2.3.1 SIG chairs
- Embedded Programming chairs: Ben Craig, Wouter van Ooijen and Odin
Holmes, John McFarlane
- Financial/Trading chairs: Robin Rowe, Staffan TjernstrÃm
Carl Cooke, Neal Horlock,
- Games chairs: Rene Riviera, Guy Davidson and Paul Hampson, Patrice Roy
- Linear Algebra chairs: Bob Steagall, Mark Hoemmen, Guy Davidson
2.4 Other Papers and proposalsRelocation: What is a trivially relocatable typeAsking SG14 to provide feedback on both proposals usefulness. Links to be sent after the callP1144 Arthuruninitialized_copy expected to get a memcpy, have a continguous range, but it is notif there are special functions, it is not copy constructible then you have to do an actual copy constructor in a looptypes that are trivially relocatable, on the object same as on the value, can relocate existing objectse.g. of these types are vector, unique_ptr,can now have a Span of objects, when number is the same, then I can move the objects around, copy/rotate/swap/permute, fastere because it is memove, smaller , more eh safe,in EWGI in Kona straw poll had no consensustop down designhttps://godbolt.org/z/o7jMo4E7e is the godbolt I was showing, btw
https://quuxplusone.github.io/blog/2018/07/13/trivially-copyable-corner-cases/Is this useful for this feature?P2786 AlisdairBottom upvolatile that is relocatble makes sense? nothing that makes it impossiblein core lang, volatile int is trivially copyable,but there are different types where it is under 1144,and under 2786protection aginst your members, like third party, or Boostthis one prefers to trust the userAO: what does that one function do? yes there is a semantic difference: trust what they read, constraint their types reasons they dont want their types to to be relocatableIN EWG in Tokyo, 16/2 forward to core, one open question to resolve the vexing parsepresented to LEWG, ok with the type traits, is it a building block?this is a compiler feature with small libraryhave clang branchcan this solve their problem in this space?
2.5 Future F2F meetings:
2.6 future C++ Standard meetings:
https://isocpp.org/std/meetings-and-participation/upcoming-meetings
-
3. Any other business
Reflector
https://lists.isocpp.org/mailman/listinfo.cgi/sg14
As well as look through papers marked "SG14" in recent standards committee
paper mailings:
http://open-std.org/jtc1/sc22/wg21/docs/papers/2015/
http://open-std.org/jtc1/sc22/wg21/docs/papers/2016/
Code and proposal Staging area
https://github.com/WG21-SG14/SG14
4. Review
4.1 Review and approve resolutions and issues [e.g., changes to SG's
working draft]
4.2 Review action items (5 min)
5. Closing process
5.1 Establish next agenda
5.2 Future meeting
* Jan 10, 2024 02:00 PM ET: Games DONE
* Feb 14, 2024 02:00 PM ET: Embedded DONE
* Mar 13, 2024 02:00 PM ET: Cancelled due to Tokyo 3-18-23
* Apr 10, 2024 02:00 PM ET: Finance
* May 8, 2024 02:00 PM ET: Games
* June 12, 2024 02:00 PM ET: Embedded; St.louis 6-24-29
* July 10, 2024 02:00 PM ET: Finance
* Aug 14, 2024 02:00 PM ET: Games
* Sep 11, 2024 02:00 PM ET: CPPCON Sept 15-20 so cancelled
* Oct 9, 2024 02:00 PM ET: Embedded
* Nov 13, 2024 02:00 PM ET: Cancelled Wroclaw F2F
* Dec 11, 2024 02:00 PM ET: Finance
SG14 mailing list
SG14@lists.isocpp.org
https://lists.isocpp.org/mailman/listinfo.cgi/sg14