pub struct OnceNonZeroUsize { /* private fields */ }
Expand description
A thread-safe cell which can be written to only once.
Implementations§
§impl OnceNonZeroUsize
impl OnceNonZeroUsize
pub const fn new() -> OnceNonZeroUsize
pub const fn new() -> OnceNonZeroUsize
Creates a new empty cell.
pub fn get(&self) -> Option<NonZeroUsize>
pub fn get(&self) -> Option<NonZeroUsize>
Gets the underlying value.
pub fn set(&self, value: NonZeroUsize) -> Result<(), ()>
pub fn set(&self, value: NonZeroUsize) -> Result<(), ()>
Sets the contents of this cell to value
.
Returns Ok(())
if the cell was empty and Err(())
if it was
full.
pub fn get_or_init<F>(&self, f: F) -> NonZeroUsizewhere
F: FnOnce() -> NonZeroUsize,
pub fn get_or_init<F>(&self, f: F) -> NonZeroUsizewhere F: FnOnce() -> NonZeroUsize,
Gets the contents of the cell, initializing it with f
if the cell was
empty.
If several threads concurrently run get_or_init
, more than one f
can
be called. However, all threads will return the same value, produced by
some f
.
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<NonZeroUsize, E>where
F: FnOnce() -> Result<NonZeroUsize, E>,
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<NonZeroUsize, E>where F: FnOnce() -> Result<NonZeroUsize, E>,
Gets the contents of the cell, initializing it with f
if
the cell was empty. If the cell was empty and f
failed, an
error is returned.
If several threads concurrently run get_or_init
, more than one f
can
be called. However, all threads will return the same value, produced by
some f
.
Trait Implementations§
§impl Debug for OnceNonZeroUsize
impl Debug for OnceNonZeroUsize
§impl Default for OnceNonZeroUsize
impl Default for OnceNonZeroUsize
§fn default() -> OnceNonZeroUsize
fn default() -> OnceNonZeroUsize
Returns the “default value” for a type. Read more
Auto Trait Implementations§
impl RefUnwindSafe for OnceNonZeroUsize
impl Send for OnceNonZeroUsize
impl Sync for OnceNonZeroUsize
impl Unpin for OnceNonZeroUsize
impl UnwindSafe for OnceNonZeroUsize
Blanket Implementations§
§impl<T> Instrument for T
impl<T> Instrument for T
§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
§impl<T> Pointable for T
impl<T> Pointable for T
§impl<T> RoundFrom<T> for T
impl<T> RoundFrom<T> for T
§fn round_from(x: T) -> T
fn round_from(x: T) -> T
Performs the conversion.
§impl<T, U> RoundInto<U> for Twhere
U: RoundFrom<T>,
impl<T, U> RoundInto<U> for Twhere U: RoundFrom<T>,
§fn round_into(self) -> U
fn round_into(self) -> U
Performs the conversion.