Struct OnceLockDefault

pub struct OnceLockDefault<T> { /* private fields */ }

A OnceLock that returns a default value if it has not been set yet.

Implementations

impl<T> OnceLockDefault<T>

pub const fn new(default: T) -> Self

Creates a new OnceLockDefault with the given default value.

pub fn set(&self, value: T) -> Result<(), T>

Initializes the contents of the cell to value.

May block if another thread is currently attempting to initialize the cell. The cell is guaranteed to contain a value when set returns, though not necessarily the one provided.

Errors

Returns Ok(()) if the cell was uninitialized and Err(value) if the cell was already initialized.

pub fn get(&self) -> &T

Gets the reference to the underlying value, if set. Otherwise returns a reference to the default value.

This method never blocks.

pub fn is_initialized(&self) -> bool

Checks if the cell has been initialized.

This method never blocks.

Trait Implementations

impl<T: Clone> Clone for OnceLockDefault<T>

fn clone(&self) -> OnceLockDefault<T>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for OnceLockDefault<T>

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

Formats the value using the given formatter.

impl<T> Deref for OnceLockDefault<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.