Macro changeset

macro_rules! changeset {
    (
        $( #[$attr:meta] )*
        pub $name:ident {
            $(
                $( #[$attrf:meta] )*
                $field:ident : $type:ty
            ),*
        }
    ) => { ... };
    (
        $( #[$attr:meta] )*
        $name:ident {
            $(
                $( #[$attrf:meta] )*
                $field:ident : $type:ty
            ),*
        }
    ) => { ... };
}