error[E0381]: used binding `x` isn't initialized --> $DIR/move-of-addr-of-mut.rs:8:5 | LL | let mut x: S; | ----- binding declared here but left uninitialized LL | std::ptr::addr_of_mut!(x); | ^^^^^^^^^^^^^^^^^^^^^^^^^ `x` used here but it isn't initialized | = note: this error originates in the macro `std::ptr::addr_of_mut` (in Nightly builds, run with -Z macro-backtrace for more info) help: consider assigning a value | LL | let mut x: S = todo!(); | +++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0381`.