Auto merge of #87140 - camsteffen:pat-slice-refs, r=oli-obk

Remove refs from Pat slices

Changes `PatKind::Or(&'hir [&'hir Pat<'hir>])` to `PatKind::Or(&'hir [Pat<'hir>])` and others. This is more consistent with `ExprKind`, saves a little memory, and is a little easier to use.

clippy_utils/src/lib.rs

@@ -255,7 +255,7 @@ pub fn in_macro(span: Span) -> bool {
 }
 
 /// Checks if given pattern is a wildcard (`_`)
-pub fn is_wild<'tcx>(pat: &impl std::ops::Deref<Target = Pat<'tcx>>) -> bool {
+pub fn is_wild(pat: &Pat<'_>) -> bool {
     matches!(pat.kind, PatKind::Wild)
 }
 
@@ -1023,8 +1023,8 @@ pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool {
         )
     }
 
-    fn are_refutable<'a, I: Iterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, mut i: I) -> bool {
-        i.any(|pat| is_refutable(cx, pat))
+    fn are_refutable<'a, I: IntoIterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_>, i: I) -> bool {
+        i.into_iter().any(|pat| is_refutable(cx, pat))
     }
 
     match pat.kind {
@@ -1035,23 +1035,23 @@ pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool {
         PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id),
         PatKind::Or(pats) => {
             // TODO: should be the honest check, that pats is exhaustive set
-            are_refutable(cx, pats.iter().map(|pat| &**pat))
+            are_refutable(cx, pats)
         },
-        PatKind::Tuple(pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)),
+        PatKind::Tuple(pats, _) => are_refutable(cx, pats),
         PatKind::Struct(ref qpath, fields, _) => {
             is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat))
         },
         PatKind::TupleStruct(ref qpath, pats, _) => {
-            is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats.iter().map(|pat| &**pat))
+            is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats)
         },
-        PatKind::Slice(head, ref middle, tail) => {
+        PatKind::Slice(head, middle, tail) => {
             match &cx.typeck_results().node_type(pat.hir_id).kind() {
                 rustc_ty::Slice(..) => {
                     // [..] is the only irrefutable slice pattern.
                     !head.is_empty() || middle.is_none() || !tail.is_empty()
                 },
                 rustc_ty::Array(..) => {
-                    are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat))
+                    are_refutable(cx, head.iter().chain(middle).chain(tail.iter()))
                 },
                 _ => {
                     // unreachable!()
@@ -1066,7 +1066,7 @@ pub fn is_refutable(cx: &LateContext<'_>, pat: &Pat<'_>) -> bool {
 /// the function once on the given pattern.
 pub fn recurse_or_patterns<'tcx, F: FnMut(&'tcx Pat<'tcx>)>(pat: &'tcx Pat<'tcx>, mut f: F) {
     if let PatKind::Or(pats) = pat.kind {
-        pats.iter().copied().for_each(f);
+        pats.iter().for_each(f);
     } else {
         f(pat);
     }