cpp version back to c++17

include/sp/protocol/MessageBase.h

@@ -122,7 +122,7 @@ class MessageImplFieldsReadBase : public TBase {
   protected:
 	void ReadImpl(DataBuffer& buffer) override {
 		auto& allFields = this->GetFields();
-		std::apply([&buffer, this]<typename T>(T& field) { 
+		std::apply([&buffer, this](auto& field) { 
 			this->ReadData(field.GetValue(), buffer); 
 		}, allFields);
 	}
@@ -133,7 +133,7 @@ class MessageImplFieldsWriteBase : public TBase {
   protected:
 	void WriteImpl(DataBuffer& buffer) override {
 		auto& allFields = this->GetFields();
-		std::apply([&buffer, this]<typename T>(T& field) { 
+		std::apply([&buffer, this](auto& field) { 
 			this->WriteData(field.GetValue(), buffer); 
 		}, allFields);
 	}

xmake.lua

@@ -1,6 +1,6 @@
 add_rules("mode.debug", "mode.release")
 
-set_languages("c++20")
+set_languages("c++17")
 
 add_requires("enet6")