Convert IList<T1> to IList<BaseT1>
<p>As the easiest way to convert the <code>IList&lt;T1&gt;</code> to <code>IList&lt;BaseT1&gt;</code>?</p>

<p><code>IList&lt;T1&gt;.Count()</code> is very large number!!!</p>

<pre><code>class BaseT1 { };
class T1 : BaseT1
{
    static public IList&lt;BaseT1&gt; convert(IList&lt;T1&gt; p)
    {
        IList&lt;BaseT1&gt; result = new List&lt;BaseT1&gt;();
        foreach (BaseT1 baseT1 in p)
            result.Add(baseT1);
        return result;
    }
}
</code></pre>
