diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index 85330c20d38e..44ca28957734 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -180,12 +180,12 @@ fn collect_unwrap_info<'tcx>( Vec::new() } -/// A HIR visitor delegate that checks if a local variable of type `Option<_>` is mutated, -/// *except* for if `Option::as_mut` is called. +/// A HIR visitor delegate that checks if a local variable of type `Option` or `Result` is mutated, +/// *except* for if `.as_mut()` is called. /// The reason for why we allow that one specifically is that `.as_mut()` cannot change -/// the option to `None`, and that is important because this lint relies on the fact that +/// the variant, and that is important because this lint relies on the fact that /// `is_some` + `unwrap` is equivalent to `if let Some(..) = ..`, which it would not be if -/// the option is changed to None between `is_some` and `unwrap`. +/// the option is changed to None between `is_some` and `unwrap`, ditto for `Result`. /// (And also `.as_mut()` is a somewhat common method that is still worth linting on.) struct MutationVisitor<'tcx> { is_mutated: bool, @@ -194,13 +194,13 @@ struct MutationVisitor<'tcx> { } /// Checks if the parent of the expression pointed at by the given `HirId` is a call to -/// `Option::as_mut`. +/// `.as_mut()`. /// /// Used by the mutation visitor to specifically allow `.as_mut()` calls. /// In particular, the `HirId` that the visitor receives is the id of the local expression /// (i.e. the `x` in `x.as_mut()`), and that is the reason for why we care about its parent /// expression: that will be where the actual method call is. -fn is_option_as_mut_use(tcx: TyCtxt<'_>, expr_id: HirId) -> bool { +fn is_as_mut_use(tcx: TyCtxt<'_>, expr_id: HirId) -> bool { if let Node::Expr(mutating_expr) = tcx.parent_hir_node(expr_id) && let ExprKind::MethodCall(path, _, [], _) = mutating_expr.kind { @@ -214,7 +214,7 @@ impl<'tcx> Delegate<'tcx> for MutationVisitor<'tcx> { fn borrow(&mut self, cat: &PlaceWithHirId<'tcx>, diag_expr_id: HirId, bk: ty::BorrowKind) { if let ty::BorrowKind::Mutable = bk && is_potentially_local_place(self.local_id, &cat.place) - && !is_option_as_mut_use(self.tcx, diag_expr_id) + && !is_as_mut_use(self.tcx, diag_expr_id) { self.is_mutated = true; } @@ -272,12 +272,10 @@ enum AsRefKind { /// If it isn't, the expression itself is returned. fn consume_option_as_ref<'tcx>(expr: &'tcx Expr<'tcx>) -> (&'tcx Expr<'tcx>, Option) { if let ExprKind::MethodCall(path, recv, [], _) = expr.kind { - if path.ident.name == sym::as_ref { - (recv, Some(AsRefKind::AsRef)) - } else if path.ident.name == sym::as_mut { - (recv, Some(AsRefKind::AsMut)) - } else { - (expr, None) + match path.ident.name { + sym::as_ref => (recv, Some(AsRefKind::AsRef)), + sym::as_mut => (recv, Some(AsRefKind::AsMut)), + _ => (expr, None), } } else { (expr, None)