What’s New in C++26? Upcoming Concurrency Features and Language Changes

ISO C++ standard committee chair and Microsoft language architect Herb Sutter announced progress on C++26, promising a “major version for concurrency and parallelism.” The committee, meeting in Varna, Bulgaria and online with about 180 members, officially approved the C++26 release schedule.

Sutter said the timeline matches that of C++23, with the final release slated for Q3 2024 and feature freeze in Q1 2025. The committee approved 40 change proposals, many of which are modest, such as adding the underscore (_) as a wildcard character and extending the basic character set with @, $, and `, similar to changes made in C23.

A notable addition is the “dangerous pointer” type, which allows only the owner to set its value while any number of threads can read it. This is valuable for lock‑free concurrent data structures that need delayed reclamation of deleted nodes, though it is not a broad memory‑safety revolution.

Sutter emphasized ongoing work on concurrency and parallelism, including std::execution and SIMD support, which will be key features of C++26.

Microsoft CTO Mark Russinovich recently suggested abandoning C/C++ for new projects in favor of Rust for safety and reliability, sparking debate in the community.

Google’s experimental Carbon project and Sutter’s own cppfront experiment are also mentioned as potential alternatives, with cppfront aiming to make C++ ten times simpler, safer, and easier to use.

Despite these explorations, the large existing C++ codebase means improvements to the language remain valuable for many developers.