/span>double_zero { <span class="keyword">static</span> <span class="keywordtype">double</span> apply() { <span class="keywordflow">return</span> 0.0; } };</div><div class="line"><a name="l00025"></a><span class="lineno">   25</span>&#160;<span class="keyword">struct </span>double_one  { <span class="keyword">static</span> <span class="keywordtype">double</span> apply() { <span class="keywordflow">return</span> 1.0; } };</div><div class="line"><a name="l00026"></a><span class="lineno">   26</span>&#160;</di