Struct Fallback 

pub struct Fallback<F, T> { /* private fields */ }

A policy that returns a fallback value when the operation fails.

This is useful for graceful degradation - instead of propagating an error, you can return a sensible default value.

Examples

use do_over::{policy::Policy, fallback::Fallback, error::DoOverError};

// Simple fallback with a static value
let policy = Fallback::new(|| "cached_data".to_string());

// Fallback that computes a value
let policy = Fallback::new(|| {
    vec!["item1".to_string(), "item2".to_string()]
});

Implementations

impl<F, T> Fallback<F, T>

where F: Fn() -> T + Send + Sync, T: Send,

pub fn new(fallback_fn: F) -> Self

Create a new fallback policy.

Arguments

• fallback_fn - A function that produces the fallback value

Examples

use do_over::fallback::Fallback;

// Return empty vec on failure
let policy = Fallback::new(|| Vec::<String>::new());

// Return a default struct
let policy = Fallback::new(|| "default".to_string());

Trait Implementations

impl<F, T> Clone for Fallback<F, T>

where F: Clone,

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<F, T, E> Policy<E> for Fallback<F, T>

where F: Fn() -> T + Send + Sync, T: Send + Sync + Clone, E: Send + Sync,

fn execute<'life0, 'async_trait, Func, Fut, R>( &'life0 self, f: Func, ) -> Pin<Box<dyn Future<Output = Result<R, E>> + Send + 'async_trait>>

where Func: Fn() -> Fut + Send + Sync + 'async_trait, Fut: Future<Output = Result<R, E>> + Send + 'async_trait, R: Send + 'async_trait, Self: 'async_trait, 'life0: 'async_trait,

Execute an async operation with this policy’s resilience behavior.