published 28. March 2024

C++, big in Japan – Michael Hava at the C++26 committee meeting

The C++ committee met from March 18 to 23, 2025 in Tokyo and continued to work on the features for C++26. This was the third of a total of nine meetings on C++26. With this meeting, half of the “feature development time” for C++26 has already been completed. A total of six meetings are planned for the development of new features and three more for the stabilization and finalization of the new standard. Michael Hava is a member of the committee and was on site as usual.

Potential new features for C++26

Potential major new features of C++26 include pattern matching, reflection and contracts. Interestingly, Reflection and Contracts were not discussed by the corresponding domain-specific sub-working groups (SG7 and SG21) for the first time during this meeting, but directly by the language and library extension groups (EWG and LEWG).

Feedback and discussions on new features

The review of Reflection was overwhelmingly positive. Pattern matching also received largely positive feedback. However, the discussion was interrupted by a magnitude 5.2 earthquake. The review of Contracts was more mixed, which is hardly surprising as the feature addresses the tension between safety and performance. Since this meeting, it has been debated whether Contracts may have to be postponed to C++29.

Michael was in Tokyo with two papers:

P2721R0: Deprecating function proposed to mark the class std::function as deprecated, as the class std::copyable_function (also introduced by Michael and already accepted) should be preferred in the future. The feedback for this expected(!) controversial topic was twofold: On the one hand, there was consensus that this should be done in the future, but there was no consensus to do this already in C++26. Michael will bring up the topic again in a few years when C++29 is being worked on and more user feedback on the necessary porting is available.
P3044R0: sub-string_view from string suggests an easier way to reference a part of a string without creating a copy. The paper was postponed to an online meeting in April prior to the meeting, but initial informal feedback was very positive. The question contained in the paper about interest in a follow-up paper that introduces something similar for continuous containers cannot yet be assessed.

The next meeting, in which Michael will only participate remotely, will take place in June in St. Louis (MO), USA.
This will be followed by the “C++ Europe Tour”:

November 2024: Wroclaw, Poland
February 2025: Hagenberg, Austria
June 2025: Sofia, Bulgaria
The last meeting for 2025 has also already been scheduled and will take place in Kona (HI), USA, in November 2025.

About the face-to-face meeting

From March 18 to 23, a face-to-face meeting of the C++ committee took place in Tokyo, Japan. Michael Hava, Senior Software Developer and C++ luminary at RISC Software GmbH, is part of this committee and therefore took part in this meeting.

Links

Status for C++

Meeting Tokyo

About Michael Hava

Michael Hava, Senior Software Developer and C++ expert at RISC Software GmbH, is part of the C++ standardization committee. He joined RISC Software in 2011 during his master studies at the University of Applied Sciences Upper Austria – Campus Hagenberg. Since then, he has promoted the introduction of modern C++ in various areas of engineering. With the aim of extending this promotion to education, he returned to his former university of applied sciences as a part-time lecturer in 2016. After attending his first C++ standardization meeting in 2019, he became a founding member of the Austrian C++ working group and serves as chair of the national committee. He remains in the LEWG most of the time and several of his papers are already accepted for C++26.