 class="special">&amp;</span><span class="special">)</span><span class="special">&gt;</span> <span class="special">{</span>
    <span class="comment">// types</span>
    <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Pair</span><span class="special">::</span><span class="identifier">first_type</span> <span class="keyword">const</span> <span class="special">&amp;</span> <a class="link" href="first/result_This_Pa_idp89315456.html#boost.proto.functional.firs