Gradual Adoption of Memory Safety?

Rust is very interesting because it has the performance of C, and it is also memory safe. However, Rust is complex and it is not super convenient to interface with C.

I think Typescript took a very smart approach. All valid javascript code is also valid typescript code, so it is possible to use ts directly with js, and even add more types to existing js over time.

Why not do a similar thing with C? Call it something like SafeC, since typescript is just js with types.