From 122793b4947c2691efcb2ab6450c251a25311aaf Mon Sep 17 00:00:00 2001
From: John Kelly <johnharrykelly@gmail.com>
Date: Tue, 2 May 2023 18:21:23 +0100
Subject: [PATCH] Update trait_bounds.rs

---
 clippy_lints/src/trait_bounds.rs | 95 ++++++++++++++------------------
 1 file changed, 42 insertions(+), 53 deletions(-)

diff --git a/clippy_lints/src/trait_bounds.rs b/clippy_lints/src/trait_bounds.rs
index ac61fb157b48..5acd44dccaf5 100644
--- a/clippy_lints/src/trait_bounds.rs
+++ b/clippy_lints/src/trait_bounds.rs
@@ -9,7 +9,7 @@ use rustc_data_structures::unhash::UnhashMap;
 use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::{
-    GenericArg, GenericBound, Generics, Item, ItemKind, MutTy, Node, Path, PathSegment, PredicateOrigin, QPath,
+    GenericArg, GenericBound, Generics, Item, ItemKind, Node, Path, PathSegment, PredicateOrigin, QPath,
     TraitBoundModifier, TraitItem, TraitRef, Ty, TyKind, WherePredicate,
 };
 use rustc_lint::{LateContext, LateLintPass};
@@ -169,59 +169,48 @@ impl<'tcx> LateLintPass<'tcx> for TraitBounds {
     }
 
     fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx Ty<'tcx>) {
-        let TyKind::Ref(
-            ..,
-            MutTy {
-                ty: Ty {
-                    kind: TyKind::TraitObject(
-                        bounds,
-                        ..
-                    ),
-                    ..
-                },
-                ..
+        if_chain! {
+            if let TyKind::Ref(.., mut_ty) = &ty.kind;
+            if let TyKind::TraitObject(bounds, ..) = mut_ty.ty.kind;
+            if bounds.len() > 2;
+            then {
+                let mut bounds_span = bounds[0].span;
+
+                for bound in bounds.iter().skip(1) {
+                    bounds_span = bounds_span.to(bound.span);
+                }
+
+                let mut seen_def_ids = FxHashSet::default();
+                let mut fixed_traits = Vec::new();
+
+                for bound in bounds.iter() {
+                    let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
+
+                    let new_trait = seen_def_ids.insert(def_id);
+
+                    if new_trait {
+                        fixed_traits.push(bound);
+                    }
+                }
+
+                if bounds.len() != fixed_traits.len() {
+                    let fixed_trait_snippet = fixed_traits
+                        .iter()
+                        .filter_map(|b| snippet_opt(cx, b.span))
+                        .collect::<Vec<_>>()
+                        .join(" + ");
+
+                    span_lint_and_sugg(
+                        cx,
+                        TRAIT_DUPLICATION_IN_BOUNDS,
+                        bounds_span,
+                        "this trait bound is already specified in trait declaration",
+                        "try",
+                        fixed_trait_snippet,
+                        Applicability::MaybeIncorrect,
+                    );
+                }
             }
-        ) = ty.kind else { return; };
-
-        if bounds.len() < 2 {
-            return;
-        }
-
-        let mut bounds_span = bounds[0].span;
-
-        for bound in bounds.iter().skip(1) {
-            bounds_span = bounds_span.to(bound.span);
-        }
-
-        let mut seen_def_ids = FxHashSet::default();
-        let mut fixed_traits = Vec::new();
-
-        for bound in bounds.iter() {
-            let Some(def_id) = bound.trait_ref.trait_def_id() else { continue; };
-
-            let new_trait = seen_def_ids.insert(def_id);
-
-            if new_trait {
-                fixed_traits.push(bound);
-            }
-        }
-
-        if bounds.len() != fixed_traits.len() {
-            let fixed_trait_snippet = fixed_traits
-                .iter()
-                .filter_map(|b| snippet_opt(cx, b.span))
-                .collect::<Vec<_>>()
-                .join(" + ");
-
-            span_lint_and_sugg(
-                cx,
-                TRAIT_DUPLICATION_IN_BOUNDS,
-                bounds_span,
-                "this trait bound is already specified in trait declaration",
-                "try",
-                fixed_trait_snippet,
-                Applicability::MaybeIncorrect,
-            );
         }
     }
 }