Macro roead::lists

macro_rules! lists {
    (@single $($x:tt)*) => { ... };
    (@count $($rest:expr),*) => { ... };
    ($($key:expr => $value:expr,)+) => { ... };
    ($($key:expr => $value:expr),*) => { ... };
}

Convenience macro to construct a ParameterListMap with map literal syntax. Example:

let plist = ParameterList {
    objects: Default::default(),
    lists: lists!(
        "somelist" => ParameterList::new()
    )
};

Adapted from https://github.com/bluss/maplit/blob/master/src/lib.rs