> This isn't much different than saying that C safe language if you write it perfectly.
The difference is in C, the entire language is unsafe, whereas in Rust only the bits marked `unsafe` are unsafe. Most Rust code does not need to use `unsafe` at all, and by extension most Rust developers don't need to touch `unsafe`. And for those developers who do use `unsafe`, instead of having to prove every single line of the program is safe like you do in C, you only have to prove that the tiny subset of the program contained within `unsafe` is safe.
The difference is in C, the entire language is unsafe, whereas in Rust only the bits marked `unsafe` are unsafe. Most Rust code does not need to use `unsafe` at all, and by extension most Rust developers don't need to touch `unsafe`. And for those developers who do use `unsafe`, instead of having to prove every single line of the program is safe like you do in C, you only have to prove that the tiny subset of the program contained within `unsafe` is safe.