title: Read-only list or unmodifiable list in .NET 4.0
body: <p>From what I can tell, .NET 4.0 still lacks read-only lists. Why does the framework still lack this functionality? Isn't this one of the commonest pieces of functionality for <a href="https://en.wikipedia.org/wiki/Domain-driven_design" rel="noreferrer">domain-driven design</a>?</p>
  
  <p>One of the few advantages Java has over C# is this in the form of the <a href="http://java.sun.com/j2se/1.3/docs/api/java/util/Collections.html#unmodifiableList(java.util.List)" rel="noreferrer">Collections.unmodifiablelist(list)</a> method, which it seems is long overdue in IList&lt;T> or List&lt;T>.</p>
  
  <p>Using <code>IEnumerable&lt;T&gt;</code> is the easiest solution to the question - <code>ToList</code> can be used and returns a copy.</p>