/// <summary>
/// Retains only the elements in this set that are contained in the specified collection.
/// </summary>
/// <param name="c">Collection that defines the set of elements to be retained.</param>
/// <returns><c>true</c> if this set changed as a result of this operation.</returns>
public sealed override bool RetainAll(ICollection c)
{
Set temp;
lock (c.SyncRoot)
{
temp = new HybridSet(c);
}
lock (_syncRoot)
{
return(_basisSet.RetainAll(temp));
}
}
/// <summary>
/// Performs an "intersection" of the two sets, where only the elements
/// that are present in both sets remain. That is, the element is included if it exists in
/// both sets. The <c>Intersect()</c> operation does not modify the input sets. It returns
/// a <c>Clone()</c> of this set with the appropriate elements removed.
/// </summary>
/// <param name="a">A set of elements.</param>
/// <returns>The intersection of this set with <c>a</c>.</returns>
public Set Intersect(Set a)
{
Set resultSet = (Set)this.Clone();
if (a != null)
{
resultSet.RetainAll(a);
}
else
{
resultSet.Clear();
}
return(resultSet);
}
