title: Maximum amount of data that can be sent using MPI::Send
body: <p>With the syntax for MPI::Isend as</p>
  
  <pre><code>MPI::Request MPI::Comm::Isend(const void *buf, int count, 
                const MPI::Datatype&amp; datatype, 
                int dest, int tag) const;
  </code></pre>
  
  <p>is the amount of data sent limited by </p>
  
  <pre><code>std::numeric_limits&lt;int&gt;::max()
  </code></pre>
  
  <p>Many other MPI functions have int parameter. Is this a limitation of MPI? </p>