meta/sqrt3.hpp

The following code example is taken from the book
C++ Templates - The Complete Guide
by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
© Copyright David Vandevoorde and Nicolai M. Josuttis 2002


#ifndef SQRT_HPP
#define SQRT_HPP

// primary template to compute sqrt(N) via iteration
template <int N, int I=1>
class Sqrt {
  public:
    enum { result = (I*I<N) ? Sqrt<N,I+1>::result
                            : I };
};

// partial specialization to end the iteration
template<int N>
class Sqrt<N,N> {
  public:
    enum { result = N };
};

#endif // SQRT_HPP