Crate tiptoe

Generic intrusive smart pointers for Rust.

The library name is a pun:

TipToe is a digit (counter) to be used as member that instances can “balance” on.

The embedded counter is designed to be as unobtrusive as possible while not in use.

Features

"sync"

Enables the Arc type, which requires AtomicUsize.

Example

Implementing IntrusivelyCountable

use pin_project::pin_project;
use tiptoe::{IntrusivelyCountable, TipToe};

// All attributes optional.
#[pin_project]
#[derive(Debug, Default, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct A {
    #[pin]
    ref_counter: TipToe,
}

unsafe impl IntrusivelyCountable for A {
    type RefCounter = TipToe;

    fn ref_counter(&self) -> &Self::RefCounter {
        &self.ref_counter
    }
}

A is now ready for use with the intrusive pointers defined in this crate.

The derived traits are optional, but included to show that TipToe doesn’t interfere here (except for Copy).

Using pin-project is optional, but very helpful if a struct should still be otherwise(!) mutable behind an intrusive pointer.

Note that A must not be Unpin (in a way that would interfere with reference-counting).

Modules

ref_counter_api

Low-level RefCounter API for custom intrusive reference-counting containers.

Structs

Arc

An asynchronously reference-counted smart pointer (copy-on-write single-item container).

ExclusivePin

A Pin<&'a mut T>, but also guarding against handle clones.

TipToe

An embeddable strong-only reference counter.

Traits

IntrusivelyCountable

Enables intrusive reference counting for a structure.

ManagedClone

Exactly like Clone but with safety restrictions regarding usage.

RefCounter

(Sealed) Common trait of tiptoe’s embeddable reference counter types.