Struct AnyPayload 

pub struct AnyPayload { /* private fields */ }

A type-erased data payload.

The only useful method on this type is AnyPayload::downcast(), which transforms this into a normal DataPayload which you can subsequently access or mutate.

As with DataPayload, cloning is designed to be cheap.

Implementations

impl AnyPayload

pub fn downcast<M>(self) -> Result<DataPayload<M>, DataError>

where M: DataMarker, M::Yokeable: ZeroFrom<'static, M::Yokeable> + MaybeSendSync, for<'a> YokeTraitHack<<M::Yokeable as Yokeable<'a>>::Output>: Clone,

Transforms a type-erased AnyPayload into a concrete DataPayload<M>.

Because it is expected that the call site knows the identity of the AnyPayload (e.g., from the data request), this function returns a DataError if the generic type does not match the type stored in the AnyPayload.

pub fn downcast_cloned<M>(&self) -> Result<DataPayload<M>, DataError>

where M: DataMarker, M::Yokeable: ZeroFrom<'static, M::Yokeable> + MaybeSendSync, for<'a> YokeTraitHack<<M::Yokeable as Yokeable<'a>>::Output>: Clone,

Clones and then transforms a type-erased AnyPayload into a concrete DataPayload<M>.

pub fn from_static_ref<Y>(static_ref: &'static Y) -> Self

where Y: for<'a> Yokeable<'a>,

Creates an AnyPayload from a static reference to a data struct.

Examples

use icu_provider::hello_world::*;
use icu_provider::prelude::*;
use std::borrow::Cow;

const HELLO_DATA: HelloWorldV1<'static> = HelloWorldV1 {
    message: Cow::Borrowed("Custom Hello World"),
};

let any_payload = AnyPayload::from_static_ref(&HELLO_DATA);

let payload: DataPayload<HelloWorldV1Marker> =
    any_payload.downcast().expect("TypeId matches");
assert_eq!("Custom Hello World", payload.get().message);

Trait Implementations

impl Clone for AnyPayload

fn clone(&self) -> AnyPayload

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AnyPayload

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

Formats the value using the given formatter.

impl<'a> Yokeable<'a> for AnyPayload

where Self: Sized,

type Output = AnyPayload

This type MUST be Self with the 'static replaced with 'a, i.e. Self<'a>

fn transform(&self) -> &Self::Output

This method must cast self between &'a Self<'static> and &'a Self<'a>.

fn transform_owned(self) -> Self::Output

This method must cast self between Self<'static> and Self<'a>.

unsafe fn make(this: Self::Output) -> Self

This method can be used to cast away Self<'a>’s lifetime.

fn transform_mut<F>(&'a mut self, f: F)

where F: 'static + for<'b> FnOnce(&'b mut Self::Output),

This method must cast self between &'a mut Self<'static> and &'a mut Self<'a>, and pass it to f.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 40 bytes