error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:16:5
   |
LL |     foo.a += 5;
   |     ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:17:6
   |
LL |     *foo.b += NonCopy;
   |      ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:18:6
   |
LL |     *foo.b = NonCopy;
   |      ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:20:5
   |
LL |     foo.a;
   |     ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:22:5
   |
LL |     foo.b;
   |     ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error[E0133]: access to union field is unsafe and requires unsafe function or block
  --> $DIR/union-assignop.rs:24:13
   |
LL |     foo.b = foo.b;
   |             ^^^^^ access to union field
   |
   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior

error: aborting due to 6 previous errors

For more information about this error, try `rustc --explain E0133`.