Why this erlang function is undefined?
<pre><code>iex(1)&gt; a = :erlang.timestamp
{1458, 585479, 931609}
iex(2)&gt; b = :erlang.timestamp
{1458, 585484, 197713}
iex(3)&gt; :erlang.now_diff(a,b)
** (UndefinedFunctionError) undefined function: :erlang.now_diff/2
    :erlang.now_diff({1458, 585479, 931609}, {1458, 585484, 197713})
</code></pre>

<p>So I can access erlang functions in elixir, accessing them by <code>:erlang</code>, but <a href="http://erlang.org/doc/man/timer.html" rel="nofollow">now_diff/2</a> is undefined. </p>

<p>I have a thought that this timer is not standard erlang module, and needed to be required/imported, but I can't figure out how?</p>

<p>P.S. Don't advice timex instead if it doesn't have function to calculate timestamps diff with high precision like this erlang function. I didn't find reading docs. </p>