diff --git a/src/options.rs b/src/options.rs
index 95a2ddb..7b45b27 100644
--- a/src/options.rs
+++ b/src/options.rs
@@ -91,20 +91,20 @@ impl EngineOption {
   }
 
   pub fn option_string(&self) -> String {
-    let mut option_data_string: String = "".to_owned();
+    let mut option_data_string: String = String::new();
 
-    for (ref dt, ref eod) in &self.option_data {
-      let dts = match dt {
+    for (ref dt, ref eod) in self.option_data {
+      let dts = match *dt {
         EngineOptionDataType::DefaultVal => "default",
         EngineOptionDataType::Min => "min",
         EngineOptionDataType::Max => "max",
         EngineOptionDataType::Var => "var",
       };
 
-      let res = match eod {
+      let res = match *eod {
         EngineOptionData::Int(v) => v.to_string(),
         EngineOptionData::Float(v) => v.to_string(),
-        EngineOptionData::Text(v) => v.cloned(),
+        EngineOptionData::Text(v) => v,
       };
 
       option_data_string.push_str(&format!("{} {:?} ", dts, res));