Question

Has anyone had to assign a list to an ISet? How do I go about and do this?

Say I have the class

class Foo
{
  ISet<Item> Items { get; set; }
}

Now, I want to do the following:

var foo = new Foo() { Items = new List<Item>() { new Item() } }

Answer 1

List<Item> myList = ...
foo.Items = new HashSet<Item>( myList );

Keep in mind that a Set, unlike a List, must contain every element exactly once. Therefore, if myList contains multiple copies of some elements, all those copies, except one, will not make it into the set.

Equality of elements (for detecting multiple copies) is defined by the Equals and GetHashCode methods. If you would like to use a different definition of equality, you can use the overload of HashSet constructor that takes an IEqualityComparer<Item>.