compact-rc

Low-memory reference-counting pointers.

The types in this crate have almost the same methods as standard Rc and Arc. The differences from the standard type is as follows:

• Weak reference is not supported.
• Small integers can be used as refcount.

Due to the differences, some methods such as weak_count are not provided.

Warnings

Using this crate with dynamically sized types (DSTs) like Rc<str> is not recommended. Some implementations in this crate rely on unspecified layout of fat pointer. So, DSTs may cause problems if the layout is changed in the future.

Sample code

use compact_rc::Rc8;

fn main() {
    // rc1 is a pointer containing i8 value with u8 refcount.
    let rc1: Rc8<i8> = Rc8::new(100);

    assert_eq!(Rc8::strong_count(&rc1), 1);
    assert_eq!(*rc1, 100);

    // Increment the refcount.
    // The value is shared by rc1 and rc2.
    let rc2 = rc1.clone();

    assert_eq!(Rc8::strong_count(&rc1), 2);
    assert_eq!(Rc8::strong_count(&rc2), 2);
    assert_eq!(*rc1, 100);
    assert_eq!(*rc2, 100);
}