You can still leak memory via a container. You can still create deadlocks. You can still throw a panic (with a backtrace). It does not solve the halting problem. But if it compiles you will not have any form of undefined behavior. No reading or writing out of bounds. No use after free, no dangling pointers, and no data getting modified across threads in an inconsistent way. If it needs a lock, the compiler will tell you with an error.

> If it needs a lock, the compiler will tell you with an error.

Oh that's what I was getting at, that makes Rust pretty much a must-have tool to have in your tool-belt.