use struct in serialize impl

card_game/src/lib.rs

@@ -653,20 +653,6 @@ where
 	}
 }
 
-#[cfg_attr(
-	feature = "serde",
-	derive(serde_derive::Deserialize),
-	serde(bound(deserialize = "
-		G: serde::Deserialize<'de>,
-		SessionConfig<G::Config>: serde::Deserialize<'de>,
-		Vec<G::Instruction>: serde::Deserialize<'de>,
-	"))
-)]
-struct SerializedSession<G: Game> {
-	config: SessionConfig<G::Config>,
-	state: G,
-	history: Vec<G::Instruction>,
-}
 #[cfg(feature = "serde")]
 impl<'de, G: Game<Score = i32>> serde::de::Deserialize<'de> for Session<G>
 where
@@ -680,6 +666,17 @@ where
 	where
 		D: serde::Deserializer<'de>,
 	{
+		#[derive(serde_derive::Deserialize)]
+		#[serde(bound(deserialize = "
+			G: serde::Deserialize<'de>,
+			SessionConfig<G::Config>: serde::Deserialize<'de>,
+			Vec<G::Instruction>: serde::Deserialize<'de>,
+		"))]
+		struct SerializedSession<G: Game> {
+			config: SessionConfig<G::Config>,
+			state: G,
+			history: Vec<G::Instruction>,
+		}
 		let serialized = SerializedSession::deserialize(deserializer)?;
 		let mut session = Session::new(serialized.state, serialized.config);
 		for instruction in serialized.history {
@@ -719,8 +716,18 @@ where
 			}
 		}
 
-		use serde::ser::SerializeStruct;
-		let mut map = serializer.serialize_struct("Session", 3)?;
+		#[derive(serde_derive::Serialize)]
+		#[serde(bound(serialize = "
+			G: serde::Serialize,
+			SessionConfig<G::Config>: serde::Serialize,
+			G::Instruction: serde::Serialize,
+		"))]
+		struct SerializedSession<'a, G: Game> {
+			config: &'a SessionConfig<G::Config>,
+			state: &'a G,
+			history: History<'a, G>,
+		}
+
 		// serialize the initial state of the game.
 		// if there is history, it is the first snapshot's state,
 		// otherwise it is the current game state since there are no moves.
@@ -729,9 +736,11 @@ where
 		} else {
 			&self.state.state
 		};
-		map.serialize_field("config", &self.config)?;
-		map.serialize_field("state", state)?;
-		map.serialize_field("history", &History(&self.state.history))?;
-		map.end()
+		let session = SerializedSession {
+			config: &self.config,
+			state,
+			history: History(&self.state.history),
+		};
+		session.serialize(serializer)
 	}
 }