Implement Parcel for array types

src/primitives/array.rs

@@ -47,6 +47,69 @@ impl<S: primitives::Integer, T: Parcel> Parcel for DynArray<S, T>
     }
 }
 
+macro_rules! impl_parcel_for_array {
+    ($n:expr) => {
+        impl<T: Parcel> Parcel for [T; $n] where T: Copy {
+            fn read(read: &mut Read) -> Result<Self, Error> {
+                use std::mem;
+
+                let mut elements: Vec<T> = Vec::with_capacity($n);
+
+                for _ in 0..$n {
+                    let elem = T::read(read)?;
+                    elements.push(elem);
+                }
+
+                let mut array: [T; $n] = unsafe { mem::uninitialized() };
+                array.clone_from_slice(&elements[..]);
+
+                Ok(array)
+            }
+
+            fn write(&self, write: &mut Write) -> Result<(), Error> {
+                for elem in self.iter() {
+                    elem.write(write)?;
+                }
+
+                Ok(())
+            }
+        }
+    }
+}
+
+impl_parcel_for_array!(1);
+impl_parcel_for_array!(2);
+impl_parcel_for_array!(3);
+impl_parcel_for_array!(4);
+impl_parcel_for_array!(5);
+impl_parcel_for_array!(6);
+impl_parcel_for_array!(7);
+impl_parcel_for_array!(8);
+impl_parcel_for_array!(9);
+impl_parcel_for_array!(10);
+impl_parcel_for_array!(11);
+impl_parcel_for_array!(12);
+impl_parcel_for_array!(13);
+impl_parcel_for_array!(14);
+impl_parcel_for_array!(15);
+impl_parcel_for_array!(16);
+impl_parcel_for_array!(17);
+impl_parcel_for_array!(18);
+impl_parcel_for_array!(19);
+impl_parcel_for_array!(20);
+impl_parcel_for_array!(21);
+impl_parcel_for_array!(22);
+impl_parcel_for_array!(23);
+impl_parcel_for_array!(24);
+impl_parcel_for_array!(25);
+impl_parcel_for_array!(26);
+impl_parcel_for_array!(27);
+impl_parcel_for_array!(28);
+impl_parcel_for_array!(29);
+impl_parcel_for_array!(30);
+impl_parcel_for_array!(31);
+impl_parcel_for_array!(32);
+
 impl<T: Parcel> Parcel for Vec<T>
 {
     fn read(read: &mut Read) -> Result<Self, Error> {
@@ -58,4 +121,22 @@ impl<T: Parcel> Parcel for Vec<T>
     }
 }
 
+#[cfg(test)]
+mod test {
+    use Parcel;
+    use std::io::Cursor;
 
+    #[test]
+    fn can_read_array() {
+        let mut data = Cursor::new([0u8, 1, 2, 3]);
+        let read_back: [u8; 4] = Parcel::read(&mut data).unwrap();
+        assert_eq!(read_back, [0, 1, 2, 3]);
+    }
+
+    #[test]
+    fn can_write_array() {
+        let mut buffer = Cursor::new(Vec::new());
+        [5u8, 7, 9, 11].write(&mut buffer).unwrap();
+        assert_eq!(buffer.into_inner(), vec![5, 7, 9, 11]);
+    }
+}