/* The following code example is taken from the book * "C++ Templates - The Complete Guide" * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002 * * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002. * Permission to copy, use, modify, sell and distribute this software * is granted provided this copyright notice appears in all copies. * This software is provided "as is" without express or implied * warranty, and with no claim as to its suitability for any purpose. */#include "ifthenelse.hpp"// primary template for main recursive steptemplate<int N, int LO=1, int HI=N>class Sqrt {  public:    // compute the midpoint, rounded up    enum { mid = (LO+HI+1)/2 };    // search a not too large value in a halved interval    typedef typename IfThenElse<(N<mid*mid),                                Sqrt<N,LO,mid-1>,                                Sqrt<N,mid,HI> >::ResultT            SubT;    enum { result = SubT::result };};// partial specialization for end of recursion criteriontemplate<int N, int S>class Sqrt<N, S, S> {  public:    enum { result = S };};