Hmm, well the benchmarks always use an explicit "faster than idiomatic C/C++ and safe Rust". Similarly it also notes that in theory you could write equally fast C/C++ (since Goose compiles to C), but it would be an unreadable, unsafe mess.

Note also the fact that e.g. array indexing has bounds checks without escape hatches for the programmer, but the compiler can elide quite a few of them, and the language has tools to help the programmer write code that is guaranteed to be check-free.

I think that suggests the ambition is to compete with Rust in the domain of combining safety with not compromising on performance.

Goose has no undefined behavior.