Fix dyn trait

Author: dingelish

src/decision_tree.rs

@@ -1746,7 +1746,7 @@ impl DecisionTree {
     /// let node: Value = serde_json::from_str(data).unwrap();
     /// let dt = DecisionTree::get_from_xgboost(&node);
     /// ```
-    pub fn get_from_xgboost(node: &serde_json::Value) -> Result<Self, Box<Error>> {
+    pub fn get_from_xgboost(node: &serde_json::Value) -> Result<Self, Box<dyn Error>> {
         // Parameters are not used in prediction process, so we use default parameters.
         let mut tree = DecisionTree::new();
         let index = tree.tree.add_root(BinaryTreeNode::new(DTNode::new()));
@@ -1759,7 +1759,7 @@ impl DecisionTree {
         &mut self,
         index: TreeIndex,
         node: &serde_json::Value,
-    ) -> Result<(), Box<Error>> {
+    ) -> Result<(), Box<dyn Error>> {
         {
             let node_ref = self
                 .tree
@@ -1798,7 +1798,7 @@ impl DecisionTree {
                 } else if missing == right_child {
                     node_ref.value.missing = 1;
                 } else {
-                    let err: Box<Error> = From::from("not support extra missing node".to_string());
+                    let err: Box<dyn Error> = From::from("not support extra missing node".to_string());
                     return Err(err);
                 }
             }
@@ -1835,7 +1835,7 @@ impl DecisionTree {
         }
 
         if (!find_left) || (!find_right) {
-            let err: Box<Error> = From::from("children not found".to_string());
+            let err: Box<dyn Error> = From::from("children not found".to_string());
             return Err(err);
         }
         Ok(())

src/gradient_boost.rs

@@ -707,7 +707,7 @@ impl GBDT {
     /// // Save model.
     /// // gbdt.save_model("gbdt.model");
     /// ```
-    pub fn save_model(&self, filename: &str) -> Result<(), Box<Error>> {
+    pub fn save_model(&self, filename: &str) -> Result<(), Box<dyn Error>> {
         let mut file = File::create(filename)?;
         let serialized = serde_json::to_string(self)?;
         file.write_all(serialized.as_bytes())?;
@@ -726,7 +726,7 @@ impl GBDT {
     ///
     /// # Error
     /// Error when get exception during model file parsing or deserialize.
-    pub fn load_model(filename: &str) -> Result<Self, Box<Error>> {
+    pub fn load_model(filename: &str) -> Result<Self, Box<dyn Error>> {
         let mut file = File::open(filename)?;
         let mut contents = String::new();
         file.read_to_string(&mut contents)?;
@@ -746,7 +746,7 @@ impl GBDT {
     ///
     /// # Error
     /// Error when get exception during model file parsing.
-    pub fn from_xgoost_dump(model_file: &str, objective: &str) -> Result<Self, Box<Error>> {
+    pub fn from_xgoost_dump(model_file: &str, objective: &str) -> Result<Self, Box<dyn Error>> {
         let tree_file = File::open(&model_file)?;
         let reader = BufReader::new(tree_file);
         let mut all_lines: Vec<String> = Vec::new();

src/input.rs

@@ -286,7 +286,7 @@ pub fn infer(file_name: &str) -> InputFormat {
 ///
 /// # Error
 /// Raise error if file cannot be read correctly.
-pub fn load_csv(file: &mut File, input_format: InputFormat) -> Result<DataVec, Box<Error>> {
+pub fn load_csv(file: &mut File, input_format: InputFormat) -> Result<DataVec, Box<dyn Error>> {
     file.seek(SeekFrom::Start(0))?;
     let mut dv = Vec::new();
 
@@ -337,7 +337,7 @@ pub fn load_csv(file: &mut File, input_format: InputFormat) -> Result<DataVec, B
 ///
 /// # Error
 /// Raise error if file cannot be read correctly.
-pub fn load_txt(file: &mut File, input_format: InputFormat) -> Result<DataVec, Box<Error>> {
+pub fn load_txt(file: &mut File, input_format: InputFormat) -> Result<DataVec, Box<dyn Error>> {
     file.seek(SeekFrom::Start(0))?;
     let mut dv = Vec::new();
 
@@ -414,7 +414,7 @@ pub fn load_txt(file: &mut File, input_format: InputFormat) -> Result<DataVec, B
 ///
 /// # Error
 /// Raise error if file cannot be open correctly.
-pub fn load(file_name: &str, input_format: InputFormat) -> Result<DataVec, Box<Error>> {
+pub fn load(file_name: &str, input_format: InputFormat) -> Result<DataVec, Box<dyn Error>> {
     let mut file = File::open(file_name.to_string())?;
     match input_format.ftype {
         FileFormat::CSV => load_csv(&mut file, input_format),