Safe C++ proposal for memory safety flames out

Work on the Safe C++ extensions proposal, forged a year ago to address memory safety in the language, has ceased, according to Harry Bott, the CEO of the C++ Alliance, which oversaw the proposal. The plan lost out to safety profiles from C++ founder Bjarne Stroustrup.

“Yes, work on Safe C++ within ISO has been discontinued,” Bott said September 29 in response to an InfoWorld email inquiry. The C++ Safety and Security SG/EWG (Study Group/Evolution Working Group) committee prioritized safety profiles from Stroustrup instread, Bott said. The poll was 19 for Profiles, nine for Safe C++, 11 for both, and six neutral. “Profiles moved forward as an incremental, backward‑compatible path feasible for C++26 timelines,” Bott said. “By contrast, Safe C++ did not reach committee consensus and was seen to imply fundamental redesign and high specification/implementation risk, with broad ecosystem‑migration concerns. Profiles were also viewed as the fastest practical response to regulatory pressure for memory safety.” Thus C++ safety work continues via Profiles and related library and tooling efforts in the committee.

Safe C++ extensions were intended to offer C++ developers memory-safe implementations of essential data structures and algorithms, along with features that prevent common memory-related errors. C++, along with the C language, had been the target of criticism by the Biden White House over memory safety concerns. However, Sean Baxter, a key advocate of the Safe C++ proposal, said earlier this month that he stopped working on the plan late last year. “The C++ committee acted quickly to express that this wasn’t the preferred way forward,” Baxter said in a September 15 email.

Stroustrup, meanwhile, was critical of the Safe ++ proposal. He disputed the notion that the proposal was a subset of C++, saying the plan was eliminating almost all good/safe C++ code. “It only addressed memory safety,” Stroustrup said in an email September 24. “My [view] is that there are many kinds of safety and that they can be addressed by Profiles, which unfortunately didn’t make C++26.”  

The C++ 26 version of the language was reported to be feature-complete in June by ISO C++ standards committee chair Herb Sutter. Release of C++ 26, with features such as compile-time reflection, is expected in 2026. Reflection is expected to improve the way code is written and expand the expressiveness of the language, Sutter wrote at the time.