Struct icu_provider::any::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 + 'static,
    M::Yokeable: ZeroFrom<'static, M::Yokeable>,
    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 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::prelude::*;
use icu_provider::hello_world::*;
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);

pub fn from_rc_payload<M>(rc_payload: Rc<DataPayload<M>>) -> Self where
    M: DataMarker + 'static, 

Creates an AnyPayload from a DataPayload stored in an Rc.

Examples

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

let payload: DataPayload<HelloWorldV1Marker> =
    DataPayload::from_owned(HelloWorldV1 {
        message: Cow::Borrowed("Custom Hello World")
    });
let rc_payload = Rc::from(payload);

let any_payload = AnyPayload::from_rc_payload(rc_payload);

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 copy 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

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.

impl<'a> IsCovariant<'a> for AnyPayload