Crate fillet 

Fillet is a thin pointer based contiguous collection.

Fillet is null/zero when empty, and is especially well suited to scenarios where most collections are empty, and you are storing references to many of them.

Fillet has specialized handling of Zero-Sized Types (ZSTs). When T is zero-sized, Fillet<T> is a usize length, and Deref and Drop behaviors are handled with dangling pointers.

Fillet is guaranteed to be pointer-sized, and is always zero (either None of NonNull or 0usize) when empty.

Fillet does not reserve capacity, and this means that repeated push can be slow since it always calls the allocator, and always computes a Layout. Fillet’s Extend and FromIterator use amortized growth and track capacity internally, so are roughly equivalent in performance to the same implementations on Vec.

Examples

Basic Usage

use fillet::Fillet;

let mut f: Fillet<_> = (1..=3).collect();
assert_eq!(f.len(), 3);
assert_eq!(*f, [1, 2, 3]);

f.push(4);
assert_eq!(*f, [1, 2, 3, 4]);

f.truncate(2);
assert_eq!(*f, [1, 2]);

Zero-Sized Types

use fillet::Fillet;
use core::iter::repeat_n;
use core::mem::size_of;

let mut f: Fillet<()> = repeat_n((), 5).collect();
assert_eq!(f.len(), 5);

// No heap allocation
f.push(());
assert_eq!(f.len(), 6);
assert_eq!(size_of::<Fillet<()>>(), size_of::<usize>());

Extending from Within

use fillet::Fillet;

let mut f = Fillet::from([1, 2]);
f.extend_from_within(..);
assert_eq!(*f, [1, 2, 1, 2]);

Structs

FilletIntoIter

A double-ended iterator over Fillet<T> that consumes and drops the collection.

Unions

Fillet

A thin pointer based contiguous collection.