pub struct OnceBool { /* private fields */ }
Expand description
A thread-safe cell which can be written to only once.
Implementations§
source§impl OnceBool
impl OnceBool
sourcepub 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.
sourcepub fn get_or_init<F>(&self, f: F) -> bool
pub fn get_or_init<F>(&self, f: F) -> 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
.
sourcepub fn get_or_try_init<F, E>(&self, f: F) -> Result<bool, E>
pub fn get_or_try_init<F, E>(&self, f: F) -> 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 !Freeze for OnceBool
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> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more