Except when escape out to unsafe (as a lot of rust code does) or stop using rust because the borrow checker is brain dead: https://github.com/rust-lang/rust/is

Except when escape out to unsafe (as a lot of rust code does) or stop using rust because the borrow checker is brain dead: https://github.com/rust-lang/rust/issues/6268 https://github.com/rust-lang/rust/issues/6268 https://github.com/rust-lang/rust/issues/6393 https://github.com/rust-lang/rust/issues/6393 Those bugs are 2 years old. And heaven forbid you have &mut self in a object.