fix(rust): Fix inconsistency between code and comment (#19810)

crates/polars-arrow/src/array/primitive/mutable.rs

@@ -370,7 +370,7 @@ impl<T: NativeType> MutablePrimitiveArray<T> {
 
     /// Sets values.
     /// # Panic
-    /// Panics iff the values' length is not equal to the existing validity's len.
+    /// Panics iff the values' length is not equal to the existing values' len.
     pub fn set_values(&mut self, values: Vec<T>) {
         assert_eq!(values.len(), self.values.len());
         self.values = values;

crates/polars-core/src/chunked_array/object/mod.rs

@@ -145,7 +145,7 @@ where
 
     /// Sets the validity of this array.
     /// # Panics
-    /// This function panics iff `values.len() != self.len()`.
+    /// This function panics iff `validity.len() != self.len()`.
     #[inline]
     pub fn set_validity(&mut self, validity: Option<Bitmap>) {
         if matches!(&validity, Some(bitmap) if bitmap.len() != self.len()) {

crates/polars-parquet/src/parquet/encoding/mod.rs

@@ -14,6 +14,7 @@ pub use crate::parquet::parquet_bridge::Encoding;
 /// This function panics iff `values.len() < 4`.
 #[inline]
 pub fn get_length(values: &[u8]) -> Option<usize> {
+    assert!(values.len() >= 4);
     values
         .get(0..4)
         .map(|x| u32::from_le_bytes(x.try_into().unwrap()) as usize)

crates/polars-parquet/src/parquet/encoding/uleb128.rs

@@ -62,6 +62,7 @@ pub fn decode(values: &[u8]) -> (u64, usize) {
 /// # Panic
 /// This function may panic if `container.len() < 10` and `value` requires more bytes.
 pub fn encode(mut value: u64, container: &mut [u8]) -> usize {
+    assert!(container.len() >= 10);
     let mut consumed = 0;
     let mut iter = container.iter_mut();
     loop {