C++26 is done! — Trip report: March 2026 ISO C++ standards meeting (London Croydon, UK)

The ISO C++ committee has completed technical work on C++26, marking what Herb Sutter calls the most compelling C++ release since C++11. The four headline features are: (1) compile-time reflection, described as the biggest upgrade since templates; (2) memory safety improvements including elimination of UB for uninitialized local variables and a hardened standard library with bounds safety, already deployed at Google and Apple at massive scale; (3) contracts (pre/post conditions and contract_assert), adopted despite sustained minority opposition; and (4) std::execution, a unified async/concurrency framework. GCC already has reflection and contracts merged in trunk. The committee also adopted the C++29 schedule, with further memory safety improvements and type safety profiles as a major focus. The final document will be sent for international approval ballot before ISO publication.