Rust's mutability rules specifically screw you over here (you can't have two mutable references to the same object, ever); most languages (including Java) don't

Rust's mutability rules specifically screw you over here (you can't have two mutable references to the same object, ever); most languages (including Java) don't have those rules. I sometimes wish I could have a mode of Rust where I had to satisfy the lifetime rules but not the at-most-one-mutable-reference-to-an-object rule.