Derive Macro ReferenceType

#[derive(ReferenceType)]
{
    // Attributes available to this derive:
    #[reference]
}

A derive macro for defining custom reference types.

For example:

#[derive(Clone, Debug, PartialEq, Eq, ReferenceType)]
#[reference(instance_of = "Error")]
pub struct Error( Reference );

#[derive(Clone, Debug, PartialEq, Eq, ReferenceType)]
#[reference(instance_of = "TypeError")]
#[reference(subclass_of(Error))]
pub struct TypeError( Reference );

And then you can do:

// You can use `try_into` to cast a `Value` to your type.
let error: TypeError = js!( return new TypeError(); ).try_into().unwrap();

// You can also pass your type freely into the `js!` macro:
js!( console.log( @{error} ); );