use option_arg_ty

Author: ada4a

clippy_lints/src/matches/try_err.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet_with_applicability;
-use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::ty::{is_type_diagnostic_item, option_arg_ty};
 use clippy_utils::{get_parent_expr, is_res_lang_ctor, path_res};
 use rustc_errors::Applicability;
 use rustc_hir::LangItem::ResultErr;
@@ -116,9 +116,7 @@ fn poll_option_result_error_type<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) ->
     if let ty::Adt(def, subst) = ty.kind()
         && cx.tcx.lang_items().get(LangItem::Poll) == Some(def.did())
         && let ready_ty = subst.type_at(0)
-        && let ty::Adt(ready_def, ready_subst) = ready_ty.kind()
-        && cx.tcx.is_diagnostic_item(sym::Option, ready_def.did())
-        && let some_ty = ready_subst.type_at(0)
+        && let Some(some_ty) = option_arg_ty(cx, ready_ty)
         && let ty::Adt(some_def, some_subst) = some_ty.kind()
         && cx.tcx.is_diagnostic_item(sym::Result, some_def.did())
     {