Fix clippy warnings

Author: tachiniererin

src/config.rs

@@ -6,10 +6,10 @@ use std::ffi::CString;
 use std::os::raw::c_char;
 use std::ptr;
 
-use strum::{EnumString, ToString};
+use strum::{Display, EnumString};
 
 /// duckdb access mode, default is Automatic
-#[derive(Debug, Eq, PartialEq, EnumString, ToString)]
+#[derive(Debug, Eq, PartialEq, EnumString, Display)]
 pub enum AccessMode {
     /// Access mode of the database AUTOMATIC
     #[strum(to_string = "AUTOMATIC")]
@@ -23,7 +23,7 @@ pub enum AccessMode {
 }
 
 /// duckdb default order, default is Asc
-#[derive(Debug, Eq, PartialEq, EnumString, ToString)]
+#[derive(Debug, Eq, PartialEq, EnumString, Display)]
 pub enum DefaultOrder {
     /// The order type, ASC
     #[strum(to_string = "ASC")]
@@ -34,7 +34,7 @@ pub enum DefaultOrder {
 }
 
 /// duckdb default null order, default is nulls first
-#[derive(Debug, Eq, PartialEq, EnumString, ToString)]
+#[derive(Debug, Eq, PartialEq, EnumString, Display)]
 pub enum DefaultNullOrder {
     /// Null ordering, NullsFirst
     #[strum(to_string = "NULLS_FIRST")]
@@ -46,6 +46,7 @@ pub enum DefaultNullOrder {
 
 /// duckdb configuration
 /// Refer to https://github.com/duckdb/duckdb/blob/master/src/main/config.cpp
+#[derive(Default)]
 pub struct Config {
     config: Option<ffi::duckdb_config>,
 }
@@ -123,12 +124,6 @@ impl Config {
     }
 }
 
-impl Default for Config {
-    fn default() -> Config {
-        Config { config: None }
-    }
-}
-
 impl Drop for Config {
     fn drop(&mut self) {
         if self.config.is_some() {

src/lib.rs

@@ -418,7 +418,7 @@ impl Connection {
             .query(params)?
             .get_expected_row()
             .map_err(E::from)
-            .and_then(|r| f(r))
+            .and_then(f)
     }
 
     /// Prepare a SQL statement for execution.

src/row.rs

@@ -168,7 +168,7 @@ where
         self.rows
             .next()
             .transpose()
-            .map(|row_result| row_result.and_then(|row| (map)(row)))
+            .map(|row_result| row_result.and_then(map))
     }
 }
 
@@ -193,7 +193,7 @@ where
         self.rows
             .next()
             .transpose()
-            .map(|row_result| row_result.map_err(E::from).and_then(|row| (map)(row)))
+            .map(|row_result| row_result.map_err(E::from).and_then(map))
     }
 }
 

src/statement.rs

@@ -279,7 +279,7 @@ impl Statement<'_> {
         P: Params,
         F: FnOnce(&Row<'_>) -> Result<T>,
     {
-        self.query(params)?.get_expected_row().and_then(|r| f(r))
+        self.query(params)?.get_expected_row().and_then(f)
     }
 
     /// Return the row count