error[E0594]: cannot assign to `x.0`, as `x` is not declared as mutable --> $DIR/reassignment_immutable_fields_twice.rs:7:5 | LL | x.0 = 1; | ^^^^^^^ cannot assign | help: consider changing this to be mutable | LL | let mut x: (u32, u32); | +++ error[E0381]: partially assigned binding `x` isn't fully initialized --> $DIR/reassignment_immutable_fields_twice.rs:12:5 | LL | let x: (u32, u32); | - binding declared here but left uninitialized LL | x.0 = 1; | ^^^^^^^ `x` partially assigned here but it isn't fully initialized | = help: partial initialization isn't supported, fully initialize the binding with a default value and mutate it, or use `std::mem::MaybeUninit` error: aborting due to 2 previous errors Some errors have detailed explanations: E0381, E0594. For more information about an error, try `rustc --explain E0381`.