Attribute Macro icu_provider::data_struct

#[data_struct]

The #[data_struct] attribute should be applied to all types intended for use in a DataStruct.

It does the following things:

• Apply #[derive(Yokeable, ZeroFrom)]. The ZeroFrom derive can be customized with #[zerofrom(clone)] on non-ZeroFrom fields.

In addition, the attribute can be used to implement DynamicDataMarker and/or DataMarker by adding symbols with optional marker path strings:

use icu::locale::fallback::*;
use icu_provider::prelude::*;
use std::borrow::Cow;

#[icu_provider::data_struct(
    FooV1Marker,
    BarV1Marker = "demo/bar@1",
    marker(
        BazV1Marker,
        "demo/baz@1",
        fallback_by = "region",
    )
)]
pub struct FooV1<'data> {
    message: Cow<'data, str>,
};

// Note: FooV1Marker implements `DynamicDataMarker` but not `DataMarker`.
// The other two implement `DataMarker`.

assert_eq!(BarV1Marker::INFO.path.as_str(), "demo/bar@1");
assert_eq!(
    BarV1Marker::INFO.fallback_config.priority,
    LocaleFallbackPriority::Language
);

assert_eq!(BazV1Marker::INFO.path.as_str(), "demo/baz@1");
assert_eq!(
    BazV1Marker::INFO.fallback_config.priority,
    LocaleFallbackPriority::Region
);