Impl Encode/Decode for smart pointers (Sovereign-Labs#12)

Cargo.toml

@@ -18,3 +18,4 @@ proptest =  { version = "1.0.0", optional = true }
 
 [features]
 fuzzing = ["proptest"]
+sync = []

src/node/db/errors.rs

@@ -10,6 +10,8 @@ pub enum CodecError {
     DeserializationError(#[from] DeserializationError),
     #[error(transparent)]
     Wrapped(#[from] anyhow::Error),
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
 }
 
 pub fn convert_to_codec_error(e: impl Into<anyhow::Error>) -> CodecError {

src/state_machine/serial.rs

@@ -1,3 +1,7 @@
+#[cfg(feature = "sync")]
+use std::sync::Arc;
+use std::{ops::Deref, rc::Rc};
+
 use thiserror::Error;
 
 #[derive(Debug, PartialEq, Error)]
@@ -30,3 +34,37 @@ pub trait Decode: Sized {
 
     fn decode(target: &mut &[u8]) -> Result<Self, Self::Error>;
 }
+
+// Automatically implement encode for smart pointers
+impl<T, U> Encode for T
+where
+    T: Deref<Target = U>,
+    U: Encode,
+{
+    fn encode(&self, target: &mut impl std::io::Write) {
+        self.deref().encode(target)
+    }
+}
+
+#[cfg(feature = "sync")]
+impl<T, E> Decode for Arc<T>
+where
+    T: Decode<Error = E>,
+{
+    type Error = E;
+
+    fn decode(target: &mut &[u8]) -> Result<Self, Self::Error> {
+        Ok(Arc::new(T::decode(target)?))
+    }
+}
+
+impl<T, E> Decode for Rc<T>
+where
+    T: Decode<Error = E>,
+{
+    type Error = E;
+
+    fn decode(target: &mut &[u8]) -> Result<Self, Self::Error> {
+        Ok(Rc::new(T::decode(target)?))
+    }
+}