</p>

    <p>C++:</p>
<pre>
void foo(std::vector&lt;double&gt;&amp; array)
{
  for(std::size_t i=0;i&lt;array.size();i++) {
    array[i] *= 2;
  }
}
</pre>
    Python:
<pre>
&gt;&gt;&gt; l = [1, 2, 3]
&gt;&gt;&gt; foo(l)
&gt;&gt;&gt; print l
[2, 4, 6]
</pre>
    Custom lvalue converters require changes to the Boost.Python core library
    and are currently not available.

    <p>P.S.:</p>

    <p>The "scitbx" files referenced above are available via anonymous
    CVS:</p>
<pre>
cvs -d:pserver:anonymous@cvs.