Add a default length of 64 to SparseChunk.

CHANGELOG.md

@@ -10,6 +10,7 @@ Versioning](http://semver.org/spec/v2.0.0.html).
 
 ### ADDED
 
+- `SparseChunk` now has a default length of `U64`.
 - `Chunk` now has `PartialEq` defined for anything that can be borrowed as a
   slice.
 - `Chunk` has a new method `capacity()` which returns its maximum capacity (the

src/sparse_chunk.rs

@@ -12,6 +12,8 @@ use std::ops::IndexMut;
 use std::ptr;
 use std::slice::{from_raw_parts, from_raw_parts_mut};
 
+use typenum::U64;
+
 use crate::bitmap::{Bitmap, Iter as BitmapIter};
 use crate::types::{Bits, ChunkLength};
 
@@ -52,7 +54,7 @@ use crate::types::{Bits, ChunkLength};
 /// ```
 ///
 /// [Unsigned]: https://docs.rs/typenum/1.10.0/typenum/marker_traits/trait.Unsigned.html
-pub struct SparseChunk<A, N: Bits + ChunkLength<A>> {
+pub struct SparseChunk<A, N: Bits + ChunkLength<A> = U64> {
     map: Bitmap<N>,
     data: ManuallyDrop<N::SizedType>,
 }