Comment by Panzerschrek

> Because of this, Ante code can safely have multiple mutable borrow references to the same struct at the same time.

I doubt it can work in multithreaded code. Allowing sharing mutable references (even to simple structs) means race conditions, temporal inconsistency between different struct fields and even incorrect read results for basic integer types (if the target CPU can't atomically read/write values of types like u64).