error[E0658]: exclusive range pattern syntax is experimental --> $DIR/feature-gate-exclusive-range-pattern.rs:3:9 | LL | 0 .. 3 => {} | ^^^^^^ | = note: see issue #37854 for more information = help: add `#![feature(exclusive_range_pattern)]` to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.