Clean up needlessly complex equality check

Author: notriddle

clippy_lints/src/casts/ptr_as_ptr.rs

@@ -4,7 +4,7 @@ use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::source::snippet_with_applicability;
 use clippy_utils::sugg::Sugg;
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, Mutability, QPath, TyKind};
+use rustc_hir::{Expr, ExprKind, QPath, TyKind};
 use rustc_lint::LateContext;
 use rustc_middle::ty;
 use rustc_span::{Span, sym};
@@ -31,8 +31,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &Expr<'tcx>, msrv: Msrv)
         && let (cast_from, cast_to) = (cx.typeck_results().expr_ty(cast_expr), cx.typeck_results().expr_ty(expr))
         && let ty::RawPtr(_, from_mutbl) = cast_from.kind()
         && let ty::RawPtr(to_pointee_ty, to_mutbl) = cast_to.kind()
-        && matches!((from_mutbl, to_mutbl),
-            (Mutability::Not, Mutability::Not) | (Mutability::Mut, Mutability::Mut))
+        && from_mutbl == to_mutbl
         // The `U` in `pointer::cast` have to be `Sized`
         // as explained here: https://github.com/rust-lang/rust/issues/60602.
         && to_pointee_ty.is_sized(cx.tcx, cx.typing_env())

clippy_lints/src/casts/ptr_cast_constness.rs

@@ -3,7 +3,7 @@ use clippy_utils::msrvs::{self, Msrv};
 use clippy_utils::sugg::Sugg;
 use clippy_utils::{std_or_core, sym};
 use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, Mutability, QPath};
+use rustc_hir::{self as hir, Expr, ExprKind, Mutability, QPath};
 use rustc_lint::LateContext;
 use rustc_middle::ty::{self, Ty, TypeVisitableExt};
 
@@ -19,10 +19,7 @@ pub(super) fn check<'tcx>(
 ) {
     if let ty::RawPtr(from_ty, from_mutbl) = cast_from.kind()
         && let ty::RawPtr(to_ty, to_mutbl) = cast_to.kind()
-        && matches!(
-            (from_mutbl, to_mutbl),
-            (Mutability::Not, Mutability::Mut) | (Mutability::Mut, Mutability::Not)
-        )
+        && from_mutbl != to_mutbl
         && from_ty == to_ty
         && !from_ty.has_erased_regions()
     {