From 8ea7b15271d945021d6e4ddf1993aace2b3a8a2a Mon Sep 17 00:00:00 2001
From: OEOTYAN <OEOTYAN@outlook.com>
Date: Thu, 20 Jun 2024 18:11:35 +0800
Subject: [PATCH] fix: fix optional_ref at c++20

---
 src/mc/common/wrapper/optional_ref.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/mc/common/wrapper/optional_ref.h b/src/mc/common/wrapper/optional_ref.h
index be87d3d961..75f7443fc1 100644
--- a/src/mc/common/wrapper/optional_ref.h
+++ b/src/mc/common/wrapper/optional_ref.h
@@ -113,6 +113,8 @@ class optional_ref {
     [[nodiscard]] constexpr decltype(auto) rbegin() const { return (get().rbegin()); }
     [[nodiscard]] constexpr decltype(auto) crend() const { return (get().crend()); }
     [[nodiscard]] constexpr decltype(auto) crbegin() const { return (get().crbegin()); }
+
+#if _HAS_CXX23
     template <class Fn>
     constexpr auto and_then(Fn&& fn) const {
         using Ret = std::invoke_result_t<Fn, T&>;
@@ -153,6 +155,7 @@ class optional_ref {
             return std::invoke(std::forward<Fn>(fn));
         }
     }
+#endif // _HAS_CXX23
 };
 // NOLINTEND
 template <typename T>