Trait icu_provider::marker::DataMarker

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pub trait DataMarker {
    type Yokeable: for<'a> Yokeable<'a>;
}

Expand description

Trait marker for data structs. All types delivered by the data provider must be associated with something implementing this trait.

By convention, the non-standard Marker suffix is used by types implementing DataMarker.

In addition to a marker type implementing DataMarker, the following impls must also be present for the data struct:

impl<'a> Yokeable<'a> (required)
impl ZeroFrom<Self>

See also some common pre-made DataMarker impls in this module.

Examples

Implementing DataMarker for a custom type:

use icu_provider::prelude::*;
use icu_provider::yoke::*;
use icu_provider::zerofrom::*;
use std::borrow::Cow;
use std::rc::Rc;

#[derive(Yokeable, ZeroFrom)]
struct MyDataStruct<'data> {
    message: Cow<'data, str>,
}

struct MyDataStructMarker;

impl DataMarker for MyDataStructMarker {
    type Yokeable = MyDataStruct<'static>;
}

// We can now use MyDataStruct with DataProvider:
let s = MyDataStruct {
    message: Cow::Owned("Hello World".into())
};
let payload = DataPayload::<MyDataStructMarker>::from_owned(s);
assert_eq!(payload.get().message, "Hello World");