ate</span> &lt;<span class="keyword">typename</span> Concept&gt;</div><div class="line"><a name="l00050"></a><span class="lineno">   50</span>&#160;    <span class="keywordtype">void</span> gil_function_requires() { function_requires&lt;Concept&gt;(); }</div><div class="line"><a name="l00051"></a><span class="lineno">   51</span>&#160;<span class="preprocessor">#else</span></div><div class="line"><a name="l00052"></a><span class="lineno">   52</span>&#160;<span class="preprocessor">    #define BOOST_GIL_CLA