error[E0302]: cannot assign in a pattern guard --> $DIR/borrowck-mutate-in-guard.rs:10:25 | LL | Enum::A(_) if { x = Enum::B(false); false } => 1, | ^^^^^^^^^^^^^^^^^^ assignment in pattern guard error[E0301]: cannot mutably borrow in a pattern guard --> $DIR/borrowck-mutate-in-guard.rs:15:38 | LL | Enum::A(_) if { let y = &mut x; *y = Enum::B(false); false } => 1, | ^ borrowed mutably in pattern guard | = help: add `#![feature(bind_by_move_pattern_guards)]` to the crate attributes to enable error[E0302]: cannot assign in a pattern guard --> $DIR/borrowck-mutate-in-guard.rs:15:41 | LL | Enum::A(_) if { let y = &mut x; *y = Enum::B(false); false } => 1, | ^^^^^^^^^^^^^^^^^^^ assignment in pattern guard error[E0510]: cannot assign `x` in match guard --> $DIR/borrowck-mutate-in-guard.rs:10:25 | LL | match x { | - value is immutable in match guard LL | Enum::A(_) if { x = Enum::B(false); false } => 1, | ^^^^^^^^^^^^^^^^^^ cannot assign error[E0510]: cannot mutably borrow `x` in match guard --> $DIR/borrowck-mutate-in-guard.rs:15:33 | LL | match x { | - value is immutable in match guard ... LL | Enum::A(_) if { let y = &mut x; *y = Enum::B(false); false } => 1, | ^^^^^^ cannot mutably borrow error: aborting due to 5 previous errors Some errors have detailed explanations: E0301, E0302, E0510. For more information about an error, try `rustc --explain E0301`.