The banner one is memory safety without garbage collection. This enables is a terrific degree of library composition. Unlike C/C++, you can generally expect that libraries you pull in will also be memory safe.
The other one is thread safety, due to the compiler-enforced ownership semantics that prevent threads from accessing shared data unless they do so in a well-defined way.
The other one is thread safety, due to the compiler-enforced ownership semantics that prevent threads from accessing shared data unless they do so in a well-defined way.