/// <summary>Returns the first element of a sequence, or a default value if the sequence contains no elements.</summary>
/// <returns>default(<typeparamref name="TSource" />) if <paramref name="source" /> is empty; otherwise, the first element in <paramref name="source" />.</returns>
/// <param name="source">The <see cref="IBindableCollection{TElement}" /> to return the first element of.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> is null.</exception>
public static IBindable <TSource> FirstOrDefault <TSource>(this IBindableCollection <TSource> source)
{
source.ShouldNotBeNull("source");
return(source.ElementAtOrDefault(0));
}
/// <summary>Returns the last element of a sequence, or a default value if the sequence contains no elements.</summary>
/// <returns>default(<typeparamref name="TSource" />) if the source sequence is empty; otherwise, the last element in the <see cref="IBindableCollection{TElement}" />.</returns>
/// <param name="source">An <see cref="IBindableCollection{TElement}" /> to return the last element of.</param>
/// <typeparam name="TSource">The type of the elements of <paramref name="source" />.</typeparam>
/// <exception cref="T:System.ArgumentNullException">
/// <paramref name="source" /> is null.</exception>
public static IBindable <TSource> LastOrDefault <TSource>(this IBindableCollection <TSource> source)
{
return(source.ElementAtOrDefault(-1));
}
