io: add support for pointer receivers in WriteArray()

It's actually preferable to have pointer receivers for serializable types, so
this should be supported.

pkg/io/binaryWriter.go

@@ -48,9 +48,12 @@ func (w *BinWriter) WriteArray(arr interface{}) {
 		w.WriteVarUint(uint64(val.Len()))
 		for i := 0; i < val.Len(); i++ {
 			el, ok := val.Index(i).Interface().(encodable)
+			if !ok {
+				el, ok = val.Index(i).Addr().Interface().(encodable)
 				if !ok {
 					panic(typ.String() + " is not encodable")
 				}
+			}
 
 			el.EncodeBinary(w)
 		}

pkg/io/binaryrw_test.go

@@ -229,6 +229,18 @@ func (t *testSerializable) DecodeBinary(r *BinReader) {
 	r.ReadLE(t)
 }
 
+type testPtrSerializable uint16
+
+// EncodeBinary implements io.Serializable interface.
+func (t *testPtrSerializable) EncodeBinary(w *BinWriter) {
+	w.WriteLE(t)
+}
+
+// DecodeBinary implements io.Serializable interface.
+func (t *testPtrSerializable) DecodeBinary(r *BinReader) {
+	r.ReadLE(t)
+}
+
 func TestBinWriter_WriteArray(t *testing.T) {
 	var arr [3]testSerializable
 	for i := range arr {
@@ -272,6 +284,16 @@ func TestBinWriter_WriteArray(t *testing.T) {
 	w.Reset()
 	w.Err = errors.New("error")
 	require.Panics(t, func() { w.WriteArray(make(chan testSerializable)) })
+
+	// Ptr receiver test
+	var arrPtr [3]testPtrSerializable
+	for i := range arrPtr {
+		arrPtr[i] = testPtrSerializable(i)
+	}
+	w.Reset()
+	w.WriteArray(arr[:])
+	require.NoError(t, w.Err)
+	require.Equal(t, expected, w.Bytes())
 }
 
 func TestBinReader_ReadArray(t *testing.T) {