lt;E2&gt; &amp;e2);

    // (v1 - v2) [i] = v1 [i] - v2 [i]
    template&lt;class E1, class E2&gt;
    typename vector_binary_traits&lt;E1, E2, scalar_minus&lt;typename E1::value_type,
                                                        typename E2::value_type&gt; &gt;::result_type
    operator - (const vector_expression&lt;E1&gt; &amp;e1,
                 const vector_expression&lt;E2&gt; &amp;e2);</code>
</pre>
<h4>Description</h4>
<p><code>operator +</code> computes the sum of two vector
expressions.