Jonathan Müller attended the fall 2024 meeting of the ISO C++ standardization committee in Wrocław, Poland. This was the fifth meeting for the upcoming C++26 standard and the feature freeze for major C++26 features.

Trip Report: Fall ISO C++ Meeting in Wrocław, Poland

by Jonathan Müller

From the article:

For an overview of all the papers that made progress, read Herb Sutter's trip report. Contracts and profiles are the big ticket items that made the most progress this meeting. Contracts is forwarded to wording review, while still being fiercely opposed by some. Profiles is essentially standardized static analysis to improve memory safety, although some deem it ineffective. Due to various scheduling conflicts I did not attend any of the relevant discussions in these spaces. Instead, I am going to share my thoughts about ranges, relocation, and reflection.

Ranges

I've spent the first day and a half co-chairing SG 9, the study group for std::ranges. During discussions, we realized two big holes in the range library that we need to address as soon as possible. They both concern the concept of sized ranges.

The first hole is related to proposal P3179—C++ parallel range algorithms, which adds an execution policy to the algorithms in std::ranges. This makes it trivial to run multi-threaded algorithms: Instead of writing std::ranges::transform(vec, output, fn), you write std::ranges::transform(std::execution::par, vec, output, fn) and now your input is split into multiple chunks and processed in parallel.