me</span><span class="special">&lt;</span> <span class="identifier">R</span><span class="special">,</span> <span class="identifier">Pred</span> <span class="special">&gt;</span><span class="special">::</span><span class="identifier">value</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">identity</span><span class="special">&lt;</span> <span class="keyword">bool</