Function check_infinity

example/general/num_limits.cpp:81–91

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   }
   // -----------------------------------------------------------------
   bool check_infinity(void)
   {  bool ok    = true;
      Float inf  = CppAD::numeric_limits<Float>::infinity();
      Float hun  = Float(100);
      Float tmp  = Float(0);
      tmp        = inf + hun;
      ok        &= inf == tmp;
      tmp        = inf - inf;
      ok        &= CppAD::isnan( tmp );
      return ok;
   }
   // -----------------------------------------------------------------
   bool check_digits10(void)
   {  bool ok     = true;