Struct non_std::dependencies::derive_tools::dependencies::parse_display::helpers::once_cell::race::OnceBox
[−]pub struct OnceBox<T> { /* private fields */ }
Expand description
A thread-safe cell which can be written to only once.
Implementations
impl<T> OnceBox<T>
impl<T> OnceBox<T>
pub fn set(&self, value: Box<T, Global>) -> Result<(), Box<T, Global>>
pub fn set(&self, value: Box<T, Global>) -> Result<(), Box<T, Global>>
Sets the contents of this cell to value
.
Returns Ok(())
if the cell was empty and Err(value)
if it was
full.
pub fn get_or_init<F>(&self, f: F) -> &T where
F: FnOnce() -> Box<T, Global>,
pub fn get_or_init<F>(&self, f: F) -> &T where
F: FnOnce() -> Box<T, Global>,
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<&T, E> where
F: FnOnce() -> Result<Box<T, Global>, E>,
pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E> where
F: FnOnce() -> Result<Box<T, Global>, 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<T> Sync for OnceBox<T> where
T: Sync + Send,
Auto Trait Implementations
impl<T> RefUnwindSafe for OnceBox<T> where
T: RefUnwindSafe,
impl<T> Send for OnceBox<T> where
T: Send,
impl<T> Unpin for OnceBox<T>
impl<T> UnwindSafe for OnceBox<T> where
T: UnwindSafe + RefUnwindSafe,
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> IntoResult<T> for T
impl<T> IntoResult<T> for T
type Err = Infallible
fn into_result(self) -> Result<T, <T as IntoResult<T>>::Err>
sourceimpl<Target, Original> VectorizedInto<Target> for Original where
Target: VectorizedFrom<Original>,
impl<Target, Original> VectorizedInto<Target> for Original where
Target: VectorizedFrom<Original>,
sourcefn vectorized_into(self) -> Target
fn vectorized_into(self) -> Target
Performs the conversion.