Struct AtomOption 

pub struct AtomOption<T: Send + Sync + 'static> { /* private fields */ }

Like Atom<T> but allows a null/empty state.

This is useful for values that may not be present initially or can be removed at runtime.

Examples

use kovan::AtomOption;

let opt: AtomOption<String> = AtomOption::none();
assert!(opt.load().is_none());

opt.store_some(String::from("hello"));
assert_eq!(&*opt.load().unwrap(), "hello");

let taken = opt.take();
assert_eq!(taken.unwrap(), "hello");
assert!(opt.load().is_none());

Implementations

impl<T: Send + Sync + 'static> AtomOption<T>

pub fn none() -> Self

Creates an empty AtomOption.

pub fn some(val: T) -> Self

Creates an AtomOption containing val.

pub fn load(&self) -> Option<AtomGuard<'_, T>>

Loads the current value, if present.

Returns None if the atom is empty, or Some(guard) where the guard dereferences to &T.

pub fn is_none(&self) -> bool

Returns true if the atom is empty.

pub fn is_some(&self) -> bool

Returns true if the atom contains a value.

pub fn store_some(&self, val: T)

Stores a value, retiring any previous value.

pub fn store_none(&self)

Clears the atom, retiring any current value.

pub fn take(&self) -> Option<T>

Takes the value out, leaving the atom empty.

Returns Some(val) if there was a value, None otherwise.

Trait Implementations

impl<T: Send + Sync + 'static + Debug> Debug for AtomOption<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Send + Sync + 'static> Default for AtomOption<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Send + Sync + 'static> Drop for AtomOption<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Send + Sync + 'static> Send for AtomOption<T>

impl<T: Send + Sync + 'static> Sync for AtomOption<T>