namespace Invercargill {

    public delegate void ItemDelegate<T>(T item);

    public delegate bool FilterTransformDelegate<Tin, Tout>(Tin item, ref Tout? res);

    public delegate Tout TransformDelegate<Tin, Tout>(Tin item);

    public delegate TOut ZipperTransformDelegate<TFirst, TSecond, TOut>(TFirst? item1, bool item1_is_null, TSecond? item2, bool item2_is_null);

    public delegate bool PredicateDelegate<T>(T item);

    public delegate Taggregate AggregateDelegate<Taggregate, Tin>(Taggregate aggregate, Tin item);

    public delegate int CompareDelegate<T>(T a, T b);

    public delegate int BinarySearchDelegate<T>(T item);

    public delegate bool EqualityDelegate<T>(T a, T b);

    public delegate uint HashDelegate<T>(T item);

    public delegate Tout ErrorThrowingDelegate<Tin, Tout>(Tin item) throws Error;

    public delegate Tout ErrorCatchingDelegate<Tin, Tout>(Tin item, Error error);

    public delegate void DebugOutputDelegate(string output);

}