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; trait Foo:Send+Sync { fn get(&self)->i32; fn set(&mut self,i:i32); }

[derive(Debug)]

struct FF{i:i32,}; impl Foo for FF{ fn get(&self)->i32{return self.i;} fn set(&mut self,i:i32){self.i=i;} } let t=FF{i:1}; let foo:Cura>=Cura::new(Box::new(t)); let a=foo.clone(); let b=foo.clone();

{ asserteq!(a.read().get(),1); { a.alter(|s|{ s.set(2); Some(()) }); } let lock=a.read(); let v=lock; asserteq!(v.get(),2) }//lock dropped here { (*b.write()).set(3); //lock dropped here i think }

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