IEnumerable<T>
IEnumerable
Where<T>
public static IEnumerable<TSource> Where<TSource>(
this IEnumerable<TSource> source,
Func<TSource, bool> predicate
)
Cast<T>
e.Where(...)
Cast
Where
int[] xs = new[] { 1, 2, 3, 4 };
IEnumerable e = xs;
var odds = e.Cast<int>().Where(x => x % 2 == 1);