Struct MonoBox 

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

A MonoBox<T> is an atomic, lock-free, write-once Option<Box<T>>. Write-once means that a MonoBox can only transition from None to Some<Box<T>> once, and is then frozen in that state until destruction.

As a special case, when one has exclusive ownership over the MonoBox (evidenced by a &mut reference), it is possible to MonoBox::swap its contents with an arbitrary Option<Box<T>>. This non-monotonic operation is safe because the mutable references guarantees no other thread can observe the transition.

Implementations

impl<T> MonoBox<T>

pub fn new(inner: Option<Box<T>>) -> Self

Returns a fresh MonoBox that holds inner.

Use Default::default() or MonoBox::empty() for a None initial value.

pub fn empty() -> Self

Returns a fresh MonoBox that holds None.

pub fn is_none(&self) -> bool

Returns whether the MonoBox’s value is None.

pub fn is_some(&self) -> bool

Returns whether the MonoBox’s value is Some.

pub fn swap(&mut self, value: Option<Box<T>>) -> Option<Box<T>>

Returns the value previously stored in this MonoBox and replaces it with value.

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

Attempts to store value in this MonoBox. The operation succeeds iff it upgrades the MonoBox from None to Some.

Returns Ok when the store succeeds, and passes back value as Err otherwise.

pub fn store_value(&self, value: T) -> bool

Attempts to store value in this MonoBox.

Returns true on success and false if there was already some value in the MonoBox.

pub fn as_ref(&self) -> Option<&T>

Gets the value stored in this MonoBox, if any.

pub fn as_mut(&mut self) -> Option<&mut T>

Gets the value stored in this MonoBox, if any.

pub fn take(&mut self) -> Option<Box<T>>

Takes the value out of this MonoBox, leaving a None in its place.

pub fn into_inner(self) -> Option<Box<T>>

Consumes this MonoBox, returning the wrapped value, if any.

impl<T: Deref> MonoBox<T>

pub fn as_deref(&self) -> Option<&T::Target>

impl<T: DerefMut> MonoBox<T>

pub fn as_deref_mut(&mut self) -> Option<&mut T::Target>

Trait Implementations

impl<T: Debug> Debug for MonoBox<T>

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

Formats the value using the given formatter.

impl<T> Default for MonoBox<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for MonoBox<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<'a, T> From<&'a MonoBox<T>> for Option<&'a T>

fn from(mono: &'a MonoBox<T>) -> Option<&T>

Converts to this type from the input type.

impl<'a, T> From<&'a mut MonoBox<T>> for Option<&'a mut T>

fn from(mono: &'a mut MonoBox<T>) -> Option<&mut T>

Converts to this type from the input type.

impl<T> From<Box<T>> for MonoBox<T>

fn from(value: Box<T>) -> MonoBox<T>

Converts to this type from the input type.

impl<T> From<MonoBox<T>> for MonoArc<T>

fn from(mono: MonoBox<T>) -> MonoArc<T>

Converts to this type from the input type.

impl<T> From<MonoBox<T>> for Option<Box<T>>

fn from(mono: MonoBox<T>) -> Option<Box<T>>

Converts to this type from the input type.

impl<T> From<MonoBox<T>> for Option<T>

fn from(mono: MonoBox<T>) -> Option<T>

Converts to this type from the input type.

impl<T> From<Option<Box<T>>> for MonoBox<T>

fn from(value: Option<Box<T>>) -> MonoBox<T>

Converts to this type from the input type.

impl<T> From<Option<T>> for MonoBox<T>

fn from(value: Option<T>) -> MonoBox<T>

Converts to this type from the input type.

impl<T> From<T> for MonoBox<T>

fn from(value: T) -> MonoBox<T>

Converts to this type from the input type.

impl<T> Pointer for MonoBox<T>

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

Formats the value using the given formatter.