 class="special">(</span><span class="number">500</span><span class="special">);</span> <span class="comment">// 500 bit precision</span>
   <span class="comment">//</span>
   <span class="comment">// Note that the argument to tgamma is</span>
   <span class="comment">// an expression template - that's just fine here.</span>
   <span class="comment">//</span>
   <span class="identifier">mpfr_class</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">boost</span><s