Struct RefCountedSingleton 

pub struct RefCountedSingleton<T>(/* private fields */);

A reference-counted singleton whose protected data can be recreated as needed.

The protected data is created when RefCountedSingleton::get_or_init is called. That function returns an RCSRef reference to the singleton.

RCSRef instances can be cloned as needed. The last RCSRef reference drops the data. Calling RefCountedSingleton::get_or_init again recreates the data.

Implementations

impl<T> RefCountedSingleton<T>

pub fn get_or_init<E: Error>( &self, creator: impl FnOnce() -> Result<T, E>, ) -> Result<RCSRef<'_, T>, Option<E>>

Return a counted reference to the protected data if such data exists, otherwise creates a new instance of the data by calling creator().

If the lock is poisoned, then this returns Err(None). If creator() returns an error err, then this returns Err(Some(err)).

pub fn get(&self) -> Option<RCSRef<'_, T>>

Return a counted reference to the protected data if such data exists.

If such data is not instantiated, or the lock is poisoned, then this returns None.

Trait Implementations

impl<T: Debug> Debug for RefCountedSingleton<T>

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

Formats the value using the given formatter.

impl<T> Default for RefCountedSingleton<T>

fn default() -> Self

Returns the “default value” for a type.