error[E0502]: cannot borrow `u.a` as mutable because it is also borrowed as immutable --> $DIR/borrowck-union-borrow.rs:25:23 | LL | let ra = &u.a; | ---- immutable borrow occurs here LL | let rma = &mut u.a; | ^^^^^^^^ mutable borrow occurs here LL | drop(ra); | -- immutable borrow later used here error[E0506]: cannot assign to `u.a` because it is borrowed --> $DIR/borrowck-union-borrow.rs:30:13 | LL | let ra = &u.a; | ---- borrow of `u.a` occurs here LL | u.a = 1; | ^^^^^^^ assignment to borrowed `u.a` occurs here LL | drop(ra); | -- borrow later used here error[E0502]: cannot borrow `u` (via `u.b`) as mutable because it is also borrowed as immutable (via `u.a`) --> $DIR/borrowck-union-borrow.rs:46:23 | LL | let ra = &u.a; | ---- immutable borrow occurs here (via `u.a`) LL | let rmb = &mut u.b; | ^^^^^^^^ mutable borrow of `u.b` -- which overlaps with `u.a` -- occurs here LL | drop(ra); | -- immutable borrow later used here | = note: `u.b` is a field of the union `U`, so it overlaps the field `u.a` error[E0506]: cannot assign to `u.b` because it is borrowed --> $DIR/borrowck-union-borrow.rs:51:13 | LL | let ra = &u.a; | ---- borrow of `u.b` occurs here LL | u.b = 1; | ^^^^^^^ assignment to borrowed `u.b` occurs here LL | drop(ra); | -- borrow later used here error[E0502]: cannot borrow `u.a` as immutable because it is also borrowed as mutable --> $DIR/borrowck-union-borrow.rs:57:22 | LL | let rma = &mut u.a; | -------- mutable borrow occurs here LL | let ra = &u.a; | ^^^^ immutable borrow occurs here LL | drop(rma); | --- mutable borrow later used here error[E0503]: cannot use `u.a` because it was mutably borrowed --> $DIR/borrowck-union-borrow.rs:62:21 | LL | let ra = &mut u.a; | -------- borrow of `u.a` occurs here LL | let a = u.a; | ^^^ use of borrowed `u.a` LL | drop(ra); | -- borrow later used here error[E0499]: cannot borrow `u.a` as mutable more than once at a time --> $DIR/borrowck-union-borrow.rs:67:24 | LL | let rma = &mut u.a; | -------- first mutable borrow occurs here LL | let rma2 = &mut u.a; | ^^^^^^^^ second mutable borrow occurs here LL | drop(rma); | --- first borrow later used here error[E0506]: cannot assign to `u.a` because it is borrowed --> $DIR/borrowck-union-borrow.rs:72:13 | LL | let rma = &mut u.a; | -------- borrow of `u.a` occurs here LL | u.a = 1; | ^^^^^^^ assignment to borrowed `u.a` occurs here LL | drop(rma); | --- borrow later used here error[E0502]: cannot borrow `u` (via `u.b`) as immutable because it is also borrowed as mutable (via `u.a`) --> $DIR/borrowck-union-borrow.rs:78:22 | LL | let rma = &mut u.a; | -------- mutable borrow occurs here (via `u.a`) LL | let rb = &u.b; | ^^^^ immutable borrow of `u.b` -- which overlaps with `u.a` -- occurs here LL | drop(rma); | --- mutable borrow later used here | = note: `u.b` is a field of the union `U`, so it overlaps the field `u.a` error[E0503]: cannot use `u.b` because it was mutably borrowed --> $DIR/borrowck-union-borrow.rs:83:21 | LL | let ra = &mut u.a; | -------- borrow of `u.a` occurs here LL | let b = u.b; | ^^^ use of borrowed `u.a` LL | LL | drop(ra); | -- borrow later used here error[E0499]: cannot borrow `u` (via `u.b`) as mutable more than once at a time --> $DIR/borrowck-union-borrow.rs:89:24 | LL | let rma = &mut u.a; | -------- first mutable borrow occurs here (via `u.a`) LL | let rmb2 = &mut u.b; | ^^^^^^^^ second mutable borrow occurs here (via `u.b`) LL | drop(rma); | --- first borrow later used here | = note: `u.b` is a field of the union `U`, so it overlaps the field `u.a` error[E0506]: cannot assign to `u.b` because it is borrowed --> $DIR/borrowck-union-borrow.rs:94:13 | LL | let rma = &mut u.a; | -------- borrow of `u.b` occurs here LL | u.b = 1; | ^^^^^^^ assignment to borrowed `u.b` occurs here LL | drop(rma); | --- borrow later used here error: aborting due to 12 previous errors Some errors have detailed explanations: E0499, E0502, E0503, E0506. For more information about an error, try `rustc --explain E0499`.