From 0ba240509f04d11d6f87b813aa591262f1a8a47b Mon Sep 17 00:00:00 2001
From: "Zezheng.Li" <Zezheng.Li@linux.alibaba.com>
Date: Tue, 1 Aug 2023 18:33:52 +0800
Subject: [PATCH] fix

---
 include/ylt/struct_pack/struct_pack_impl.hpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/ylt/struct_pack/struct_pack_impl.hpp b/include/ylt/struct_pack/struct_pack_impl.hpp
index e91a3f8828..e0285a54f5 100644
--- a/include/ylt/struct_pack/struct_pack_impl.hpp
+++ b/include/ylt/struct_pack/struct_pack_impl.hpp
@@ -928,8 +928,11 @@ constexpr decltype(auto) get_type_literal() {
     else {
       constexpr auto id = get_type_id<Arg>();
       constexpr auto ret = string_literal<char, 1>{{static_cast<char>(id)}};
-      if constexpr (id == type_id::non_trivial_class_t ||
-                    id == type_id::trivial_class_t) {
+      if constexpr (id == type_id::monostate_t) {
+        return ret;
+      }
+      else if constexpr (id == type_id::non_trivial_class_t ||
+                         id == type_id::trivial_class_t) {
         using Args = decltype(get_types<Arg>());
         constexpr auto body = get_type_literal<Args, Arg, ParentArgs...>(
             std::make_index_sequence<std::tuple_size_v<Args>>());