fn get_map_argument<'a>(cx: &LateContext<'_>, expr: &'a Expr<'a>) -> Option<&'a [Expr<'a>]> {
if_chain! {
if let ExprKind::MethodCall(ref method, _, ref args, _) = expr.kind;
- if args.len() == 2 && method.ident.as_str() == "map";
+ if args.len() == 2 && method.ident.name == sym::map;
let caller_ty = cx.typeck_results().expr_ty(&args[0]);
if match_trait_method(cx, expr, &paths::ITERATOR)
|| is_type_diagnostic_item(cx, caller_ty, sym::result_type)