Change where we enforce endianness

rust/lance-encoding/src/buffer.rs

@@ -222,7 +222,11 @@ impl LanceBuffer {
     /// Reinterprets a LanceBuffer into a Vec<T>
     ///
     /// If the underlying buffer is not properly aligned, this will involve a copy of the data
-    #[cfg(target_endian = "little")]
+    ///
+    /// Note: doing this sort of re-interpretation generally makes assumptions about the endianness
+    /// of the data.  Lance does not support big-endian machines so this is safe.  However, if we end
+    /// up supporting big-endian machines in the future, then any use of this method will need to be
+    /// carefully reviewed.
     pub fn borrow_to_typed_slice<T: ArrowNativeType>(&mut self) -> impl AsRef<[T]> {
         let align = std::mem::align_of::<T>();
         let is_aligned = self.as_ptr().align_offset(align) == 0;

rust/lance-encoding/src/lib.rs

@@ -21,6 +21,12 @@ pub mod statistics;
 pub mod testing;
 pub mod version;
 
+// We can definitely add support for big-endian machines someday.  However, it's not a priority and
+// would involve extensive testing (probably through emulation) to ensure that the encodings are
+// correct.
+#[cfg(not(target_endian = "little"))]
+compile_error!("Lance encodings only support little-endian systems.");
+
 /// A trait for an I/O service
 ///
 /// This represents the I/O API that the encoders and decoders need in order to operate.