Question

Possible Duplicate:
Find sequence in IEnumerable<T> using Linq

There is a string method: int IndexOf(string value).
I failed to find a more generic one in Linq, something should look like this:

static int IndexOf<T>(this List<T> source,List<T> value,Predicate<T> equality)

Why Microsoft didn’t provide us a generic string search function?

Answer 1

It sounds like your referring to List<T>.FindIndex().

–EDIT–

A more general method for any IEnumerable<T> would be:-

public static int FindIndex<T>(this IEnumerable<T> source, Predicate<T> equality)
{
    return source
        .Select((item, index) => new {Item = item, Index = index})
        .First(x => equality(x.Item)).Index;
}