/// <typeparam name="TSource"></typeparam>
/// <param name="source">The System.Collections.Generic.IEnumerable<<typeparamref name="TSource"/>> to return the first element of.</param>
/// <param name="default">The default value to return if the source is empty.</param>
/// <returns><paramref name="default"/> if <paramref name="source"/> is empty or if no element passes the test specified by <paramref name="predicate"/>;
/// otherwise, the first element in <paramref name="source"/> that passes the test specified by <param name="predicate"/>.</returns>
/// <exception cref="System.ArgumentNullException"><paramref name="source"/> or <paramref name="predicate"/> is null.</exception>
public static TSource FirstOrDefault <TSource>(this IEnumerable <TSource> source, Func <TSource, Boolean> predicate, TSource @default)
{
return(DDRIT.FirstOrDefault(source, predicate, @default));
}
/// <typeparam name="TSource"></typeparam>
/// <param name="source">The System.Collections.Generic.IEnumerable<<typeparamref name="TSource"/>> to return the first element of.</param>
/// <param name="default">The default value to return if the source is empty.</param>
/// <returns><paramref name="default"/> if <paramref name="source"/> is empty; otherwise, the first element in <paramref name="source"/>.</returns>
/// <exception cref="System.ArgumentNullException"><paramref name="source"/> is null.</exception>
public static TSource FirstOrDefault <TSource>(this IEnumerable <TSource> source, TSource @default)
{
return(DDRIT.FirstOrDefault(source, @default));
}