New upstream version 1.66.0+dfsg1

[rustc.git] / src / tools / clippy / clippy_lints / src / eta_reduction.rs

diff --git a/src/tools/clippy/clippy_lints/src/eta_reduction.rs b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
index 53bc617a4f5b78929510599109619bcb29753018..7b9786d7e570f91b398f2d7ea9e4fa46cb098fdf 100644 (file)
--- a/src/tools/clippy/clippy_lints/src/eta_reduction.rs
+++ b/src/tools/clippy/clippy_lints/src/eta_reduction.rs
@@ -1,7 +1,7 @@
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
 use clippy_utils::higher::VecArgs;
 use clippy_utils::source::snippet_opt;
-use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::ty::{implements_trait, is_type_diagnostic_item};
 use clippy_utils::usage::local_used_after_expr;
 use clippy_utils::{higher, is_adjusted, path_to_local, path_to_local_id};
 use if_chain::if_chain;
@@ -11,8 +11,7 @@ use rustc_hir::{Closure, Expr, ExprKind, Param, PatKind, Unsafety};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow};
 use rustc_middle::ty::binding::BindingMode;
-use rustc_middle::ty::subst::Subst;
-use rustc_middle::ty::{self, ClosureKind, Ty, TypeVisitable};
+use rustc_middle::ty::{self, Ty, TypeVisitable};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::symbol::sym;
 
@@ -123,15 +122,12 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
             then {
                 span_lint_and_then(cx, REDUNDANT_CLOSURE, expr.span, "redundant closure", |diag| {
                     if let Some(mut snippet) = snippet_opt(cx, callee.span) {
-                        if_chain! {
-                            if let ty::Closure(_, substs) = callee_ty.peel_refs().kind();
-                            if substs.as_closure().kind() == ClosureKind::FnMut;
-                            if path_to_local(callee).map_or(false, |l| local_used_after_expr(cx, l, expr));
-
-                            then {
+                        if let Some(fn_mut_id) = cx.tcx.lang_items().fn_mut_trait()
+                            && implements_trait(cx, callee_ty.peel_refs(), fn_mut_id, &[])
+                            && path_to_local(callee).map_or(false, |l| local_used_after_expr(cx, l, expr))
+                        {
                                 // Mutable closure is used after current expr; we cannot consume it.
-                                snippet = format!("&mut {}", snippet);
-                            }
+                                snippet = format!("&mut {snippet}");
                         }
                         diag.span_suggestion(
                             expr.span,
@@ -158,7 +154,7 @@ impl<'tcx> LateLintPass<'tcx> for EtaReduction {
                     diag.span_suggestion(
                         expr.span,
                         "replace the closure with the method itself",
-                        format!("{}::{}", name, path.ident.name),
+                        format!("{name}::{}", path.ident.name),
                         Applicability::MachineApplicable,
                     );
                 })
@@ -217,9 +213,8 @@ fn check_sig<'tcx>(cx: &LateContext<'tcx>, closure_ty: Ty<'tcx>, call_ty: Ty<'tc
     if !closure_ty.has_late_bound_regions() {
         return true;
     }
-    let substs = match closure_ty.kind() {
-        ty::Closure(_, substs) => substs,
-        _ => return false,
+    let ty::Closure(_, substs) = closure_ty.kind() else {
+        return false;
     };
     let closure_sig = cx.tcx.signature_unclosure(substs.as_closure().sig(), Unsafety::Normal);
     cx.tcx.erase_late_bound_regions(closure_sig) == cx.tcx.erase_late_bound_regions(call_sig)