de> class is used to initialize, finalize, and query the MPI environment. It will typically be used in the <code class="computeroutput">main()</code> function of a program, which will create a single instance of <code class="computeroutput">environment</code> initialized with the arguments passed to the program:</p>
<pre class="programlisting">  <span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</s