apply clippy suggestions

src/cmd/frequency.rs

@@ -194,7 +194,7 @@ impl Args {
         #[allow(unused_assignments)]
         // amortize allocation
         let mut field_work: Vec<u8> = Vec::with_capacity(100);
-        let mut row_work: csv::ByteRecord = Default::default();
+        let mut row_work: csv::ByteRecord = csv::ByteRecord::default();
         let flag_no_nulls = self.flag_no_nulls;
         for row in it {
             row_work.clone_from(&row?);

src/cmd/sqlp.rs

@@ -292,7 +292,7 @@ impl OutputMode {
         };
 
         match execute_inner() {
-            Ok(_) => Ok(df.shape()),
+            Ok(()) => Ok(df.shape()),
             Err(e) => {
                 fail_clierror!("Failed to execute query: {query}: {e}")
             },

src/cmd/stats.rs

@@ -188,6 +188,7 @@ use crate::{
     util, CliResult,
 };
 
+#[allow(clippy::unsafe_derive_deserialize)]
 #[derive(Clone, Deserialize, Debug)]
 pub struct Args {
     pub arg_input:            Option<String>,

src/config.rs

@@ -349,8 +349,8 @@ impl Config {
         };
         let mut wtr = io::BufWriter::with_capacity(DEFAULT_WTR_BUFFER_CAPACITY, idxfile);
         match csv_index::RandomAccessSimple::create(&mut rdr, &mut wtr) {
-            Ok(_) => {
-                let Ok(_) = io::Write::flush(&mut wtr) else {
+            Ok(()) => {
+                let Ok(()) = io::Write::flush(&mut wtr) else {
                     return;
                 };
                 debug!("autoindex of {path_buf:?} successful.");