Unfortunately I will not be able to attend this meeting.

Cheers,
G

On Tue, 6 May 2025 at 16:44, Michael Wong via SG19 <sg19_at_[hidden]>
wrote:

> Hi all, from the notes to the Apr 10th meeting now that all papers have
> been published in the April mailing. We wishes to take a vote on these
> papers to exit SG19 to head to LEWG. Please prepare accordingly. Thank you.
>
> The group reviewed updates to five papers, focusing on descriptors in
> graph algorithms, which reduce interface complexity and improve
> performance. They also discussed the implementation of accumulator objects
> for statistical functions, considering compile-time configuration to avoid
> runtime overhead. The need for further experimentation and potential delay
> of the accumulator to a second paper was suggested. The meeting concluded
> with plans to publish updated papers by April 15 for a potential vote in
> May.
> Action Items
>
> - [ ] Publish the updated papers by this weekend so they can be
> reviewed before the next meeting.
> - [ ] Perform a final review to ensure any internal comments are
> removed from the published papers.
> - [ ] Provide the updated paper versions to the group for further
> review and feedback.
> - [ ] We intend to put these papers to a vote to exit SG19 in the May
> 8th SG19 meeting based on the updated papers from updates for the
> graph proposal that have been added to the 2025-04 mailing (ISO/IEC
> JTC1/SC22/WG21 - Papers 2025
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/>). Feedback
> welcome.
> -
> P3126R3
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3126r3.pdf> Graph
> Library: Overview Phil Ratzloff, Andrew Lumsdaine 2025-04-13 2025-04
> P3126R2
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3126r2.pdf> SG14
> Low Latency,SG19 Machine Learning
> P3127R1
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3127r1.pdf> Graph
> Library: Background and Terminology Phil Ratzloff, Andrew Lumsdaine
> 2025-04-13 2025-04 P3127R0
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3127r0.pdf> SG14
> Low Latency,SG19 Machine Learning
> P3128R3
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3128r3.pdf> Graph
> Library: Algorithms Phil Ratzloff, Andrew Lumsdaine 2025-04-13 2025-04
> P3128R2
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3128r2.pdf> SG14
> Low Latency,SG19 Machine Learning
> P3129R1
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3129r1.pdf> Graph
> Library: Views Phil Ratzloff, Andrew Lumsdaine 2025-04-13 2025-04
> P3129R0
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3129r0.pdf> SG14
> Low Latency,SG19 Machine Learning
> P3130R3
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3130r3.pdf> Graph
> Library: Graph Container Interface Phil Ratzloff, Andrew Lumsdaine
> 2025-04-13 2025-04 P3130R2
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3130r2.pdf> SG14
> Low Latency,SG19 Machine Learning
> P3131R3
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2025/p3131r3.pdf> Graph
> Library: Graph Containers Phil Ratzloff, Andrew Lumsdaine 2025-04-13
> 2025-04 P3131R2
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3131r2.pdf> SG14
> Low Latency,SG19 Machine Learning
>
>
> Michael Wong is inviting you to a scheduled Zoom meeting.
>
> Topic: SG19 monthly
> Time: 2nd Thursdays 02:00 PM Eastern Time (US and Canada)
> Every month on the Second Thu,
>
>
> Join from PC, Mac, Linux, iOS or Android:
>
> https://iso.zoom.us/j/93084591725?pwd=K3QxZjJlcnljaE13ZWU5cTlLNkx0Zz09
> Password: 035530
>
> Or iPhone one-tap :
> US: +13017158592,,93084591725# or +13126266799,,93084591725#
> Or Telephone:
> Dial(for higher quality, dial a number based on your current location):
> US: +1 301 715 8592 or +1 312 626 6799 or +1 346 248 7799 or +1
> 408 638 0968 or +1 646 876 9923 or +1 669 900 6833 or +1 253 215 8782
> or 877 853 5247 (Toll Free)
> Meeting ID: 930 8459 1725
> Password: 035530
> International numbers available: https://iso.zoom.us/u/agewu4X97
>
> Or Skype for Business (Lync):
> https://iso.zoom.us/skype/93084591725
>
> Agenda:
>
> 1. Opening and introductions
>
> The ISO Code of conduct:
> https://www.iso.org/files/live/sites/isoorg/files/store/en/PUB100397.pdf
>
> IEC Code of Conduct:
>
> https://www.iec.ch/basecamp/iec-code-conduct-technical-work
>
> ISO patent policy.
>
>
> https://isotc.iso.org/livelink/livelink/fetch/2000/2122/3770791/Common_Policy.htm?nodeid=6344764&vernum=-2
>
> The WG21 Practices and Procedures and Code of Conduct:
>
> https://isocpp.org/std/standing-documents/sd-4-wg21-practices-and-procedures
>
> 1.1 Roll call of participants
>
> 1.2 Adopt agenda
>
> 1.3 Approve minutes from 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
>
>
>
>
> * Jan 9, 2025 02:00 PM ET: Cancelled
> * Feb 13, 2025 02:00 PM ET: Hagenberg F2F; Cancelled
> * Mar 13, 2025 02:00 PM ET: Graph
> * Apr 10, 2025 02:00 PM ET: Stats
> * May 8, 2025 02:00 PM ET: Graph
> * June 12, 2025 02:00 PM ET: Stats
> * July 10, 2025 02:00 PM ET: Graphs
> * Aug 14, 2025 02:00 PM ET: Stats
> * Sep 11, 2025 02:00 PM ET: Graph, CPPCON
> * Oct 9, 2025 02:00 PM ET: Stats
> * Nov 13, 2025 02:00 PM ET: Graph
> * Dec 11, 2025 02:00 PM ET: Stats
>
>
> ISO meeting status
>
> future C++ Std meetings
>
> 2.2 Paper reviews
>
> For graph, we have a new draft of P3337 Comparison paper that compares the
> library in performance against boost::graph and NWGraph.
>
> If Andrew is able to attend, he should be able to review the changes he's
> made to P3126 and P3127.
>
>
> P3495 from Oliver/Mark
>
> >From Phil: There are updates to the P3126 Overview and P3127 Background
> and
> Terminology papers for the Graph Library. They haven’t been published yet,
> but it would be helpful to get input on them before they’re published.
>
>
>
> Since the changes are a response to Oliver’s concerns, I think Oliver and
> Andrew would need to attend to make it useful to have a session for the
> Graph Library. Unless they want to do that, I think we can send draft
> versions to the reflector, unless there’s a better idea.
>
>
> Review BSI Graph feedback:
> As Oliver (Rosten) said "The basic premise is important, and it would be
> fantastic to have support for graphs in the standard."
>
> The main items identified were:
> Oliver:
> - This paper is long and incomplete, it has lots of details which I think
> to be irrelevant, however things that are definitely relevant are missing
> from the paper - for example definition of graph - since people have
> different ideas. We need to add a mathematical perspective to the paper.
>
> - The structure of the paper completely changed in the new revision, so now
> it’s hard to understand what and why they have done
>
> - Another missing part is discussion of graph invariants
>
> Tom (Deakin): There’s a big missing part in “Prior art” part, GraphBLAS (
> https://graphblas.org) eminently.
>
> Some other things to add:
>
> 1. The electrical circuit example needs more explanation, and I think this
> will highlight some deep issues around representing things which are
> seemingly trivially graphs, as graphs in practice. In what sense is a
> bog-standard resistor directed? I assume the reason that the graph is
> directed is because current has a sign and in an undirected graph it
> becomes ambiguous which way the current is flowing (also you may want
> components like diodes). But the directed representation also has issues:
> "can current flow from 'Vdd' to 'n0'?" should be immediately answerable
> from the properties of Vdd and its edges. There are other ways to represent
> an electrical circuit. One is as a directed graph but with incident edges
> recorded - but iiuc, this is excluded from the latest version of the paper.
> Alternatively, one could have a mathematical object, the name of which I
> actually don't know: it looks like an undirected graph, but where each
> partial edge has additional, unique, end-point data, as well as the common
> weight. Things like this are the reason why I think we need a broader group
> to look at this proposal (i.e. beyond SG19) and if we possibly can we
> should involve someone from the mathematics community. Otherwise there's a
> real danger we end up missing important insights.
>
> 2. My comment about the structure of the paper changing was a reference to
> previous comparisons with boost::graph. I'm sure these were in an earlier
> version, or am I misremembering? Either way, it would be very helpful to
> have a proper discussion of e.g. the move away from visitors.
>
> 3. Re. the definition of a graph, there needs to be a proper discussion
> about whether the paper's definition of graph is what some authors call a
> multigraph and whether it does/does not include loops. These things are
> mentioned, in passing, when introducing algorithms, but terminology needs
> to be properly established.
>
> 4. I think we're trying to do too much in one go in this paper. I think a
> great first step would be to build on mdspan and try to standardize (or at
> least understand) what might reasonably be called an unstructured span.
> This could be represented as a vector of vectors or as a vector with some
> auxiliary storage indicating where the partitions fall. The point is that
> an unstructured span, with the right invariants, is an adjacency list. If
> we can understand unstructured span and its desirable api, I think this
> will be incredibly valuable guidance for what a standardized graph
> container might look like.
>
> 5. IIUC, this paper excludes pure connectivity graphs. These are incredibly
> helpful and, if I've understood correctly that they are not supported,
> would be a major omission. Another good reason, imo, to start with
> unstructured span!
>
> 6. I'm not convinced by the load api. We don't have a load api for vector
> etc. Moreover, would it not be preferable to have appropriate constructors?
>
>
> 2.2.1: ML topics
>
> 2.2.1.1 Graph Proposal Phil Ratsloff et al
>
> Latest paper:
>
> Here’s a link to the paper (different than the previous paper reviewed).
> There are some additional updates I’m planning on making before the
> meeting.
>
>
> https://docs.google.com/document/d/1OpH-xxRri7tJTtJJIZTYmSHkkrZJkdBwm9zJ7LqolfQ/edit?usp=sharing
>
>
>
>
> P1709R3:
>
> https://docs.google.com/document/d/1kLHhbSTX7j0tPeTYECQFSNx3R35Mu3xO5_dyYdRy4dM/edit?usp=sharing
>
>
> https://docs.google.com/document/d/1QkfDzGyfNQKs86y053M0YHOLP6frzhTJqzg1Ug_vkkE/edit?usp=sharing
>
> <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2119r0.html>
>
> <
>
> https://docs.google.com/document/d/175wIm8o4BNGti0WLq8U6uZORegKVjmnpfc-_E8PoGS0/edit?ts=5fff27cd#heading=h.9ogkehmdmtel
> *>*
>
> Array copy semantics:
> array copy-semantics paper P1997 "Relaxing Restrictions on Arrays",
> https://wg21.link/p1997
>
> Stats feedback:
>
> P2376R0
> <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p2376r0.pdf>
> Comments
> on Simple Statistical Functions (p1708r4): Contracts, Exceptions and
> Special cases Johan Lundberg
>
> 2.2.1.2 Reinforcement Learning Larry Lewis Jorge Silva
>
> Reinforcement Learning proposal:
>
> 2.2.1.3 Differential Calculus:
>
>
> https://docs.google.com/document/d/175wIm8o4BNGti0WLq8U6uZORegKVjmnpfc-_E8PoGS0/edit?ts=5fff27cd#heading=h.9ogkehmdmtel
>
> 2.2.1.4: Stats paper
>
> P2681R0
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2022/p2681r0.pdf>
> More
> Stats Functions Richard Dosselmann, Michael Wong
> Current github
>
> https://github.com/cplusplus/papers/issues/475
>
> https://github.com/cplusplus/papers/issues/979
>
> Stats review Richard Dosselman et al
>
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2021/p1708r4.pdf
>
> Feedback from Johan Lundberg and Oleksandr Korval
>
> https://isocpp.org/files/papers/D2376R0.pdf
>
> P1708R3: Math proposal for Machine Learning: 3rd review
>
> PXXXX: combinatorics: 1st Review
>
> *> std.org/jtc1/sc22/wg21/docs/papers/2020/p1708r2
> <http://std.org/jtc1/sc22/wg21/docs/papers/2020/p1708r2>*
> *> above is the stats paper that was reviewed in Prague*
> *> http://wiki.edg.com/bin/view/Wg21prague/P1708R2SG19
> <http://wiki.edg.com/bin/view/Wg21prague/P1708R2SG19>*
> *>*
> *> Review Jolanta Polish feedback.*
> *> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2119r0.html
> <http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2119r0.html>*
>
>
> 2.2.1.4: Matrix paper
>
> 2.2.3 any other proposal for reviews?
>
> 2.3 Other Papers and proposals
>
> P1416R1: SG19 - Linear Algebra for Data Science and Machine Learning
>
> https://docs.google.com/document/d/1IKUNiUhBgRURW-UkspK7fAAyIhfXuMxjk7xKikK4Yp8/edit#heading=h.tj9hitg7dbtr
>
> P1415: Machine Learning Layered list
>
> https://docs.google.com/document/d/1elNFdIXWoetbxjO1OKol_Wj8fyi4Z4hogfj5tLVSj64/edit#heading=h.tj9hitg7dbtr
>
> 2.2.2 SG14 Linear Algebra progress:
> Different layers of proposal
>
> https://docs.google.com/document/d/1poXfr7mUPovJC9ZQ5SDVM_1Nb6oYAXlK_d0ljdUAtSQ/edit
>
> 2.5 Future F2F meetings:
>
> 2.6 future C++ Standard meetings:
> https://isocpp.org/std/meetings-and-participation/upcoming-meetings
>
> None
>
> 3. Any other business
>
> New reflector
>
> http://lists.isocpp.org/mailman/listinfo.cgi/sg19
>
> Old Reflector
> https://groups.google.com/a/isocpp.org/forum/#!newtopic/sg19
> <https://groups.google.com/a/isocpp.org/forum/?fromgroups=#!forum/sg14>
>
> Code and proposal Staging area
>
> 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 9, 2025 02:00 PM ET: Cancelled
> * Feb 13, 2025 02:00 PM ET: Hagenberg F2F; Cancelled
> * Mar 13, 2025 02:00 PM ET: Graph
> * Apr 10, 2025 02:00 PM ET: Stats
> * May 8, 2025 02:00 PM ET: Graph
> * June 12, 2025 02:00 PM ET: Stats
> * July 10, 2025 02:00 PM ET: Graphs
> * Aug 14, 2025 02:00 PM ET: Stats
> * Sep 11, 2025 02:00 PM ET: Graph, CPPCON
> * Oct 9, 2025 02:00 PM ET: Stats
> * Nov 13, 2025 02:00 PM ET: Graph
> * Dec 11, 2025 02:00 PM ET: Stats
> --
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