c

crates/polars-io/src/mmap.rs

@@ -1,6 +1,5 @@
 use std::fs::File;
 use std::io::{BufReader, Cursor, Read, Seek};
-use std::sync::Arc;
 
 use polars_core::config::verbose;
 use polars_utils::mmap::{MMapSemaphore, MemSlice};
@@ -87,6 +86,11 @@ impl std::ops::Deref for ReaderBytes<'_> {
 /// `MemSlice` from the `ReaderBytes` in a zero-copy manner regardless of the underlying enum
 /// variant.
 impl ReaderBytes<'static> {
+    /// Construct a `MemSlice` in a zero-copy manner from the underlying bytes, with the assumption
+    /// that the underlying bytes have a `'static` lifetime. This is marked as unsafe despite having
+    /// a `'static` inner lifetime, as the `Owned(Vec<u8>)` variant is not covered by the lifetime
+    /// guarantee.
+    ///
     ///  # Safety
     /// `Self` outlives the returned `MemSlice` if this enum variant is an `Owned(Vec<u8>)`.
     pub unsafe fn to_static_slice(&self) -> MemSlice {

crates/polars-io/src/parquet/read/read_impl.rs

@@ -15,7 +15,6 @@ use polars_parquet::parquet::statistics::Statistics;
 use polars_parquet::read::{
     self, ColumnChunkMetadata, FileMetadata, Filter, PhysicalType, RowGroupMetadata,
 };
-use polars_utils::mmap::MemSlice;
 use rayon::prelude::*;
 
 #[cfg(feature = "cloud")]