/// <summary>Retrieves a reference to the specified item.</summary>
/// <typeparam name="T">The type of the items in the set.</typeparam>
/// <param name="tset">The set to search.</param>
/// <param name="item">The item sought.</param>
/// <returns>A reference to a matching item if it is present in the set, null otherwise.</returns>
/// <remarks>This allows use of the set to restrain a group of objects to exclude duplicates, allowing for
/// reduced memory use, and reference-based equality checking, comparable with how
/// <see cref="string.IsInterned(string)"/> allows one to check for a copy of a string in the CLR intern pool,
/// but also allowing for removal, clearing and multiple pools. This is clearly only valid for reference types.
/// </remarks>
public static T Find <T>(this ThreadSafeSet <T> tset, T item) where T : class
{
ThreadSafeSet <T> .Box box = tset.Obtain(item);
return(box == null ? null : box.Value);
}
