operator()(<span class="keywordtype">size_t</span> particle_index)<span class="keyword"> const </span>{ <span class="keywordflow">return</span> 1; };</div><div class="line"><a name="l00059"></a><span class="lineno">   59</span>&#160;    };</div><div class="line"><a name="l00060"></a><span class="lineno">   60</span>&#160;</div><div class="line"><a name="l00064"></a><span class="lineno"><a class="line" href="struct_s_p_h_1_1_search_depth_multi_resolution.html">   64</a></span>&#160;    <span class="keyword">