21CTO

May 17, 2026 · Fundamentals

How C++26’s Hardened Standard Library Tackles Undefined Behavior

The article explains that undefined behavior in C++ often stems from standard‑library misuse, describes the new C++26 P3471R4 hardened library that turns such UB into runtime contract violations, cites Google’s production data showing over a thousand bugs found with only 0.30% overhead and a 30% drop in segfaults, and details how to enable and use the feature.