The shared_singleton trait provides singleton pattern state management with shared container.
Implement the singleton pattern with very short code are available.
You can choose the better shared container from Rc<T>, Rc<Cell<T>>, Rc<RefCell<T>>, Arc<T>, Arc<Mutex<T>> and Arc<RwLock<T>>.
Rc<T>```rust use shared_singleton::*;
struct Foo(usize); implsingletonrc!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
assert_eq!(1, Foo::singleton().0);
assert!(std::rc::Rc::ptr_eq(&x1, &x2)); ```
Rc<Cell<T>>```rust use shared_singleton::*;
struct Foo(usize); implsingletonrc_cell!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
asserteq!(1, x1.get().0); x2.set(Foo(2)); asserteq!(2, x1.get().0);
assert!(std::rc::Rc::ptr_eq(&x1, &x2)); ```
Rc<RefCell<T>>```rust use shared_singleton::*;
struct Foo(usize); implsingletonrc_refcell!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
asserteq!(1, x1.borrow().0); x2.borrowmut().0 = 2; assert_eq!(2, x1.borrow().0);
assert!(std::rc::Rc::ptr_eq(&x1, &x2)); ```
Arc<T>```rust use shared_singleton::*;
struct Foo(usize); implsingletonarc!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
assert_eq!(1, x1.0);
assert!(std::sync::Arc::ptr_eq(&x1, &x2)); ```
Arc<Mutex<T>>```rust use shared_singleton::*;
struct Foo(usize); implsingletonarc_mutex!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
assert!(std::sync::Arc::ptr_eq(&x1, &x2));
let t1 = std::thread::spawn(move || { x1.lock().unwrap().0 = 2; println!("{}", x1.lock().unwrap().0); });
let t2 = std::thread::spawn(move || { x2.lock().unwrap().0 = 3; println!("{}", x2.lock().unwrap().0); });
t1.join().unwrap(); t2.join().unwrap(); ```
Arc<RwLock<T>>```rust use shared_singleton::*;
struct Foo(usize); implsingletonarc_rwlock!(Foo, Foo(1));
let x1 = Foo::singleton(); let x2 = Foo::singleton();
assert!(std::sync::Arc::ptr_eq(&x1, &x2));
let t1 = std::thread::spawn(move || { x1.write().unwrap().0 = 2; println!("{}", x1.read().unwrap().0); });
let t2 = std::thread::spawn(move || { x2.write().unwrap().0 = 3; println!("{}", x2.read().unwrap().0); });
t1.join().unwrap(); t2.join().unwrap(); ```