error[E0658]: multiple patterns in `if let` and `while let` are unstable (see issue #48215) --> $DIR/feature-gate-if_while_or_patterns.rs:12:5 | LL | / if let 0 | 1 = 0 { //~ ERROR multiple patterns in `if let` and `while let` are unstable LL | | ; LL | | } | |_____^ | = help: add #![feature(if_while_or_patterns)] to the crate attributes to enable error[E0658]: multiple patterns in `if let` and `while let` are unstable (see issue #48215) --> $DIR/feature-gate-if_while_or_patterns.rs:15:5 | LL | / while let 0 | 1 = 1 { //~ ERROR multiple patterns in `if let` and `while let` are unstable LL | | break; LL | | } | |_____^ | = help: add #![feature(if_while_or_patterns)] to the crate attributes to enable error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0658`.