Macro gdnative::godot_class

macro_rules! godot_class {
    (
class $name:ident: $parent:ty {
    fields {
        $(
            $(#[$fattr:meta])*
            $fname:ident : $fty:ty,
        )*
    }
    setup($builder:ident) $pbody:block
    constructor($header:ident) $construct:block

    $($tt:tt)*
}
    ) => { ... };
}