From 5fc0bc40189c67f27ffc88d3774ae76e9eba9917 Mon Sep 17 00:00:00 2001 From: Mateusz Pusz Date: Tue, 2 Jul 2024 19:30:25 +0100 Subject: [PATCH] docs: St. Louis 2024 report added --- docs/blog/posts/st.louis-2024-report.md | 73 +++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 docs/blog/posts/st.louis-2024-report.md diff --git a/docs/blog/posts/st.louis-2024-report.md b/docs/blog/posts/st.louis-2024-report.md new file mode 100644 index 00000000..62e78884 --- /dev/null +++ b/docs/blog/posts/st.louis-2024-report.md @@ -0,0 +1,73 @@ +--- +date: 2024-07-02 +authors: + - mpusz +categories: + - WG21 +--- + +# Report from the St. Louis 2024 ISO C++ Committee meeting + +We made significant progress in the standardization of this library during the ISO C++ Committee +meeting in St. Louis. + + + +## [P30942R3: `std::basic_fixed_string`](https://wg21.link/p3094r3) + +First, the `fixed_string` was unanimously forwarded from the SG18 LEWG Incubator to the Library +Evolution Working Group (LEWG). The group suggested a few minor changes to the paper, which +resulted in the R3 version of the proposal. + +The paper is in excellent shape, and the entire wording is ready as well. Hopefully +it will progress quickly through the remaining groups in the Committee. + + +## [P3045R1: Quantities and units library](https://wg21.link/p3045r1) + +In the SG6 (Numerics), we had a really efficient discussion about the recently raised usability +issues with temperatures and the Minimal Viable Product (MVP) scope. + +The following polls were taken: + +!!! question "POLL: If WG21 adds anything to the standard to provide units or quantities, then such a solution must at least include the necessary abstractions for units, dimensions, and quantity kinds. (It does not have to provide system definitions, e.g. ISQ/SI definitions.)" + + | Strongly in Favor | In favor | Neutral | Against | Strongly Against | + |:-----------------:|:--------:|:-------:|:-------:|:----------------:| + | 7 | 4 | 7 | 0 | 0 | + +!!! question "POLL: If WG21 adds anything to the standard to provide units or quantities, then such a solution must at least include the necessary abstractions for units, dimensions, quantity kinds, and quantities of the same kind. (It does not have to provide system definitions, e.g. ISQ/SI definitions.)" + + | Strongly in Favor | In favor | Neutral | Against | Strongly Against | + |:-----------------:|:--------:|:-------:|:-------:|:----------------:| + | 5 | 2 | 5 | 2 | 0 | + +!!! question "POLL: If WG21 adds anything to the standard to provide units or quantities, then such a solution must at least include the necessary abstractions for units, dimensions, quantity kinds, and affine spaces. (It does not have to provide system definitions, e.g. ISQ/SI definitions.)" + + | Strongly in Favor | In favor | Neutral | Against | Strongly Against | + |:-----------------:|:--------:|:-------:|:-------:|:----------------:| + | 5 | 0 | 8 | 1 | 0 | + +As we can see, there are no controversies about the first poll that states that the MVP should +include at least: + +- units, +- dimensions, +- quantity kinds (e.g., _frequency_ vs _activity_, _plane angle_ vs _solid angle_, + _fuel_consumption_ vs _area_). + +The next polls add either: + +- quantities of the same kind (e.g., _length_ vs _width_ vs _wavelength_, _potential energy_ vs +_kinetic energy_), +- the affine space abstractions (i.e., point origins and `quantity_point`). + +SG6 considered those less important, but no one was strongly against including those in the MVP. +We were asked to return with better motivation and usage examples for those features. + +**If you are depending on quantities of the same kind or quantity points in your project and you +would like to see them in the `std` library, please let us know about your use cases.** + +Besides SG6, we spent six hours in the SG18 LEWG Incubator discussing the details of the library +design. The proposal was very well received, and we got a few valuable comments and suggestions +that we will apply to the next version of the paper.