Find And Remove Items From Collection

Question

What is the best way to remove a set from a collection, but still keep the items that were removed in a separate collection?

I have written an extension method that

Answer 1

I don't agree that it is the most efficient - you are calling the predicate match twice on each element of the list.

I'd do it like this:

    var ret = new List(); 
    var remaining = new List(); 
    foreach (T t in lst) {
        if (match(t)) 
        { 
            ret.Add(t); 
        } 
        else 
        { 
            remaining.Add(t); 
        } 
    }
    lst.Clear();
    lst.AddRange(remaining);
    return ret;