Macro reffers::rc_bit_mask

macro_rules! rc_bit_mask {
    ($t: ty, $t_int: ty, $r:expr, $s: expr, $w: expr) => { ... };
}

If you need your own rc with custom overhead, you can invoke this macro for your own type (which is normally a newtype around an integer).

Example

#[macro_use]
extern crate reffers;
use reffers::rc::Ref;

#[derive(Debug, Copy, Clone, Default)]
struct ManyWeak(u32);

// We want 16 Refs, no Strongs, and as many Weaks as possible
// for the 32 bits of overhead that we are willing to accept.
// In total, this must add up to max 30 bits (32 bits minus 2 for status).
rc_bit_mask!(ManyWeak, u32, 4, 0, 26);

fn main() {
    let r: Ref<str, ManyWeak> = Ref::new_str("Hi!");
    // We can create weaks
    let w = r.get_weak();
    // ...but no strongs
    assert!(w.try_get_strong().is_err());
}