A sort of an Arc-RwLock combination..

That aims to be simple and straightforward to use when sharing data between threads.

An attempt at creating an Arc-RwLock combination that is straightforward to use and no hassle , instead of worrying about being fast and lean.

• cloning referefences works like Arc
• made for sharing objects between threads without worry
• locking things works like RwLock with write() or read()
• it spins a few times and then queues if a lock is not obtained
• miri seems to be happy , so i trust it doesnt leak too much memory etc.
• requires that everything you stick into it is Send+Sync
• no need to constantly .unwrap() things instead it will just block forever or blow up

Example

```rust use cura::Cura; let t:i32=1; let foo=Cura::new(t); let a=foo.clone(); let b=foo.clone();

{ asserteq!(*a.read(),1); { a.alter(|s|{ Some(2) }); } let lock=a.read(); let v=*lock; asserteq!(v,2) }//lock dropped here { (*b.write())+=1; //lock dropped here i think }

assert_eq!((*a.read()),3); ```