Struct OnceCellDropStrategy 

pub struct OnceCellDropStrategy<M: Mode> {
    pub inner: Arc<OnceCell<Error>>,
    /* private fields */
}

A try drop strategy which sets an error value once. This try drop strategy can only handle single errors. If you want to handle multiple errors, see the BroadcastDropStrategy.

The most common use case of this is when you want to get an error from inside a function which calls TryDrop.

Examples

use once_cell::sync::OnceCell;
use std::sync::Arc;
use try_drop::drop_strategies::once_cell::Ignore;
use try_drop::drop_strategies::OnceCellTryDropStrategy;

fn calls_try_drop(may_fail: ThisDropMayFail) {
    // do something with `may_fail`
}

let error = Arc::new(OnceCell::new());
let strategy = OnceCellTryDropStrategy::<Ignore>::new(Arc::clone(&error));
let may_fail = ThisDropMayFail::new_with_strategy(strategy);

calls_try_drop(may_fail);

if let Some(error) = Arc::try_unwrap(error)
    .expect("arc still referenced by `calls_try_drop`")
    .take()
{
    println!("an error occurred in `calls_try_drop`: {error}")
}

Fields

inner: Arc<OnceCell<Error>>

The inner error value.

Implementations

impl OnceCellDropStrategy<Ignore>

pub fn ignore(item: Arc<OnceCell<Error>>) -> Self

Create a new once cell drop strategy which will ignore if there is already an error value in its cell.

impl OnceCellDropStrategy<Error>

pub fn error(item: Arc<OnceCell<Error>>) -> Self

Create a new once cell drop strategy which will error if there is already an error value in its cell.

impl<M: Mode> OnceCellDropStrategy<M>

pub fn new(item: Arc<OnceCell<Error>>) -> Self

Creates a new drop strategy which sets an error value once.

Trait Implementations

impl<M: Clone + Mode> Clone for OnceCellDropStrategy<M>

fn clone(&self) -> OnceCellDropStrategy<M>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<M: Debug + Mode> Debug for OnceCellDropStrategy<M>

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

Formats the value using the given formatter.

impl<M: Default + Mode> Default for OnceCellDropStrategy<M>

fn default() -> OnceCellDropStrategy<M>

Returns the “default value” for a type.

impl FallibleTryDropStrategy for OnceCellDropStrategy<Error>

type Error = AlreadyOccupiedError

The type of the error that may occur when handling a drop error.

fn try_handle_error(&self, error: Error) -> Result<(), Self::Error>

Try and handle a drop error.

impl TryDropStrategy for OnceCellDropStrategy<Ignore>

fn handle_error(&self, error: Error)

Handle the drop error.