pub struct OnceBool { /* private fields */ }
Expand description
A thread-safe cell which can be written to only once.
Implementations§
§impl OnceBool
impl OnceBool
pub fn set(&self, value: bool) -> Result<(), ()>
pub fn set(&self, value: bool) -> 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) -> boolwhere
F: FnOnce() -> bool,
pub fn get_or_init<F>(&self, f: F) -> boolwhere F: FnOnce() -> bool,
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<bool, E>where
F: FnOnce() -> Result<bool, E>,
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<bool, E>where F: FnOnce() -> Result<bool, 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§
Auto Trait Implementations§
impl RefUnwindSafe for OnceBool
impl Send for OnceBool
impl Sync for OnceBool
impl Unpin for OnceBool
impl UnwindSafe for OnceBool
Blanket Implementations§
source§impl<T> Instrument for T
impl<T> Instrument for T
source§fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
fn instrument(self, span: Span) -> Instrumented<Self> ⓘ
source§fn in_current_span(self) -> Instrumented<Self> ⓘ
fn in_current_span(self) -> Instrumented<Self> ⓘ
§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.