error[E0502]: cannot borrow `u.a` as mutable because it is also borrowed as immutable
  --> $DIR/borrowck-union-borrow.rs:23:23
   |
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:28:13
   |
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:44:23
   |
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:49:13
   |
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:55:22
   |
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:60:21
   |
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:65:24
   |
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:70:13
   |
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:76:22
   |
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:81:21
   |
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:87:24
   |
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:92:13
   |
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`.