boost.org/doc/libs/release/doc/html/Transform.html" target="_top">Proto
            Transforms</a> are passed to <a href="http://www.boost.org/doc/libs/release/doc/html/boost/proto/functional/make_expr.html" target="_top"><code class="computeroutput"><span class="identifier">proto</span><span class="special">::</span><span class="identifier">functional</span><span class="special">::</span><span class="identifier">make_expr</span></code></a> which returns the
            freshly created expression
          