Bryce Lelbach's Kona Twitter Poll

https://www.reddit.com/r/cpp/comments/aq8rxf/bryce_lelbach_on_twitter_what_proposed_c20/

Twitter

Kona Trip Reports

• Modules! Coroutines! Contracts! Ranges! Constexpr! Spaceships! Calendars! Time zones!

• Bryce Lelbach https://www.reddit.com/r/cpp/comments/au0c4x/201902_kona_iso_c_committee_trip_report_c20/

  • The reports of modules being dead on arrival have been greatly exaggerated. https://www.reddit.com/r/cpp/comments/au0c4x/201902_kona_iso_c_committee_trip_report_c20/eh4stfg/
  • More Reddit https://www.reddit.com/r/programming/comments/au1ie3/201902_kona_iso_c_committee_trip_report_c20/
  • Hacker News https://news.ycombinator.com/item?id=19235702

• Herb Sutter https://herbsutter.com/2019/02/23/trip-report-winter-iso-c-standards-meeting-kona/

  • Reddit https://www.reddit.com/r/cpp/comments/au1skl/herbs_kona_trip_report_winter_iso_c_standards/

  At our next meeting in July, we expect to formally adopt a few additional features that were design-approved at this meeting but didn’t complete full wording specification review this week <...> (formatting, flat_map etc.)

C++20

Bryce Lelbach:

TL;DR: C++20 may well be as big a release as C++11.

API design: iterator-based vs. container-based

Pros:

• Iterator-based API is more flexible

  • works with different containers
  • works with types that expose differently-named begin and end member functions
  • works on ranges of data instead of the entire container

• Protobuf APIs are iterator-based
• Flatbuffers are iterator-based
• Standard and Boost algorithms are iterator-based

Cons:

• Not as readable as container-based API

Eigen + MTS + Google Ceres Solver = SEGFAULT

• Eigen http://eigen.tuxfamily.org/index.php?title=Main_Page
• Ceres Solver http://ceres-solver.org/

• Memory managers:

  • MTS http://www.desy.de/user/projects/C++/products/mts.html

    • for every 10000 allocations 13 to 17 were unaligned

  • TCMalloc (Google) http://goog-perftools.sourceforge.net/doc/tcmalloc.html
  • Jemalloc (FreeBSD, Facebook) http://jemalloc.net/

bool aligned = ((unsigned long)p % 16) == 0;

Cpp On Sea 2019 Trip Report by Arne Mertz

https://arne-mertz.de/2019/02/cpp-on-sea-2019-trip-report/

C++ On Sea is definitely the best conference I have ever been to.

The opener was titled “Hello, World”, there was a “main()” plenary hall and session rooms titled “const west”, “east const”, and “unsigned”. The latter was the smallest of the session rooms and had an overflow problem a few times, but luckily that did not lead to undefined behavior, because C++ conference attendees seem to be very nice people in general.

C++ Binary Compatibility and Pain-Free Upgrades to Visual Studio 2019

https://blogs.msdn.microsoft.com/vcblog/2019/01/31/cpp-binary-compatibility-and-pain-free-upgrades-to-visual-studio-2019/

Visual Studio 2019 Release Candidate (RC) now available

https://devblogs.microsoft.com/visualstudio/visual-studio-2019-release-candidate-rc-now-available/

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