/// <summary>
/// Returns a future that indicates whether all values
/// yielded by the data-producer satisfy a given condition.
/// The future will return true for an empty sequence or
/// where all values satisfy the condition, else false
/// (if any value value fails to satisfy the condition).
/// </summary>
/// <param name="source">The data-producer to be monitored.</param>
/// <param name="predicate">The condition that must be satisfied by all terms.</param>
public static IFuture <bool> All <TSource>(this IDataProducer <TSource> source, DotNet20.Func <TSource, bool> predicate)
{
predicate.ThrowIfNull("predicate");
return(FutureProxy <bool> .FromFuture(source.Any(value => !predicate(value)), value => !value));
}