Struct Singleton

pub struct Singleton<T: Send + Sync> { /* private fields */ }

A pointer type for holding shared global state in multi-thread environment.

Implementations

impl<T: Send + Sync> Singleton<T>

pub fn new() -> Self

Create an uninitialized singleton.

pub fn get(&self) -> &T

where T: Default,

Access the singleton; initialize it with Default::default() if it is uninitialized.

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

Access the singleton; or return None if it is not yet uninitialized.

pub fn get_or_insert_with<F>(&self, f: F) -> &T

where F: FnOnce() -> T,

Access the singleton; initialize it with custom function if it is uninitialized.

pub unsafe fn finalize(&self)

Put the singleton into a finalized state, destruct the singleton value if it is initialized.

This is unsafe and only useful when the value holds other resources.

Trait Implementations

impl<T: Send + Sync> Default for Singleton<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Send + Sync> Drop for Singleton<T>

fn drop(&mut self)

Executes the destructor for this type.