Attribute Macro dyn_object 

#[dyn_object]

Available on crate feature macros only.

Make a trait compatible with DynObject.

Arguments

• bounds: Additional bounds, e.g. Send, allowing to use DynObject<dyn Trait + Send>.

Examples

// Allows using both `DynObject<dyn Future>` and `DynObject<dyn Future + Send>`
#[dyn_object]
#[dyn_object(bounds = Send)]
trait Callback {
    fn call(&self, arg: &str);
}

impl<F: Fn(&str)> Callback for F {
    fn call(&self, arg: &str) {
        self(arg)
    }
}

// no allocation
let callback = DynObject::<dyn Callback>::new(|arg: &str| println!("{arg}"));

Limitations

When combined to dyn_trait, generic parameters are not supported.

#[dyn_utils::dyn_trait(trait = DynCallback)]
#[dyn_trait(dyn_utils::dyn_object)]
trait Callback<T> {
    fn call(&self, arg: T) -> impl Future<Output = ()> + Send;
}

When possible, using associated types instead overcomes this limitation

#[dyn_utils::dyn_trait(trait = DynCallback)]
#[dyn_trait(dyn_utils::dyn_object)]
trait Callback {
    type Arg;
    fn call(&self, arg: Self::Arg) -> impl Future<Output = ()> + Send;
}