src/tools/clippy/clippy_lints/src/matches/wild_in_or_pats.rs

   1 use clippy_utils::diagnostics::span_lint_and_help;
   2 use clippy_utils::is_wild;
   3 use rustc_hir::{Arm, PatKind};
   4 use rustc_lint::LateContext;
   5
   6 use super::WILDCARD_IN_OR_PATTERNS;
   7
   8 pub(crate) fn check(cx: &LateContext<'_>, arms: &[Arm<'_>]) {
   9     for arm in arms {
  10         if let PatKind::Or(fields) = arm.pat.kind {
  11             // look for multiple fields in this arm that contains at least one Wild pattern
  12             if fields.len() > 1 && fields.iter().any(is_wild) {
  13                 span_lint_and_help(
  14                     cx,
  15                     WILDCARD_IN_OR_PATTERNS,
  16                     arm.pat.span,
  17                     "wildcard pattern covers any other pattern as it will match anyway",
  18                     None,
  19                     "consider handling `_` separately",
  20                 );
  21             }
  22         }
  23     }
  24 }