>Over the past decades, in addition to large Java and Go memory-safe codebases, Google has developed and accumulated hundreds of millions of lines of C++ code t

>Over the past decades, in addition to large Java and Go memory-safe codebases, Google has developed and accumulated hundreds of millions of lines of C++ code that is in active use and under active, ongoing development. This very large existing codebase results in significant challenges for a transition to memory safety: We see no realistic path for an evolution of C++ into a language with rigorous memory safety guarantees that include temporal safety. A large-scale rewrite of all existing C++ code into a different, memory-safe language appears very difficult and will likely remain impractical[0]. [0] https://security.googleblog.com/2024/03/secure-by-design-googles-perspective-on.html#:~:text=Over%20the%20past,likely%20remain%20impractical https://security.googleblog.com/2024/03/secure-by-design-goo.... Long story short; they are stuck with millions of C++ LOC and they can't transition to Rust completely because of the enormous complexity of various gigantic codebases e.g. Android, Chrome or whatever they want to move to memory-safe language/s. They said they will try to write as much new native code in Rust as they can plus they will interop from C++ to Rust in order to reduce memory-safety bugs.