| error[E0658]: the `#[pattern_complexity]` attribute is just used for rustc unit tests and will never be stable | |
| --> $DIR/feature-gate-pattern-complexity.rs:3:1 | |
| | | |
| LL | #![pattern_complexity = "42"] | |
| | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
| | | |
| = help: add `#![feature(rustc_attrs)]` to the crate attributes to enable | |
| = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date | |
| error: aborting due to 1 previous error | |
| For more information about this error, try `rustc --explain E0658`. |