Struct icu_provider::marker::NeverMarker

pub struct NeverMarker<Y>(PhantomData<Y>);

A DataMarker that never returns data.

All types that have non-blanket impls of DataProvider<M> are expected to explicitly implement DataProvider<NeverMarker<Y>>, returning DataErrorKind::MissingDataKey. See impl_data_provider_never_marker!.

Examples

use icu_locid::langid;
use icu_provider::hello_world::*;
use icu_provider::prelude::*;
use icu_provider::NeverMarker;

let buffer_provider = HelloWorldProvider.into_json_provider();

let result = DataProvider::<NeverMarker<HelloWorldV1<'static>>>::load(
    &buffer_provider.as_deserializing(),
    DataRequest {
        locale: &langid!("en").into(),
        metadata: Default::default(),
    },
);

assert!(matches!(
    result,
    Err(DataError {
        kind: DataErrorKind::MissingDataKey,
        ..
    })
));

Tuple Fields

0: PhantomData<Y>

Trait Implementations

impl<Y: Clone> Clone for NeverMarker<Y>

fn clone(&self) -> NeverMarker<Y>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<Y> DataMarker for NeverMarker<Y>

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

type Yokeable = Y

A type that implements Yokeable. This should typically be the 'static version of a data struct.

impl<Y: Debug> Debug for NeverMarker<Y>

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

Formats the value using the given formatter.

impl<Y> KeyedDataMarker for NeverMarker<Y>

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

const KEY: DataKey = _

The single DataKey associated with this marker.

fn bind<P>(provider: P) -> DataProviderWithKey<Self, P>

where P: DataProvider<Self>, Self: Sized,

Binds this KeyedDataMarker to a provider supporting it.

impl<Y: Copy> Copy for NeverMarker<Y>