Macro define_props

macro_rules! define_props {
    (
        $(#[$struct_meta:meta])*
        $vis:vis struct $name:ident {
            $(
                $(#[$field_meta:meta])*
                $field_vis:vis $field_name:ident: $field_type:ty
            ),*
            $(,)?
        }
    ) => { ... };
}

Type-safe builder for props