</span><span class="keyword">typename</span> Pair<span class="special">&gt;</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.html#idp89320480-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">P