1 error[E0506]: cannot assign to `a1` because it is borrowed
2 --> $DIR/regions-pattern-typing-issue-19997.rs:10:13
5 | --- borrow of `a1` occurs here
7 LL | a1 = &f; //[ast]~ ERROR cannot assign
8 | ^^^^^^^ assignment to borrowed `a1` occurs here
9 LL | //[mir]~^ ERROR cannot assign to `a1` because it is borrowed
11 | -- borrow later used here
13 error: aborting due to previous error
15 For more information about this error, try `rustc --explain E0506`.