Example 1: Compile-time Square Root Computation: ceil(sqrt(N)) 

(Note: I found this snippet on the web somewhere)


     // <root.h>:

     template <int Size, int Low = 1, int High = Size> 
       struct Root;
      
     template <int Size, int Mid>                     
       struct Root<Size,Mid,Mid> { 
           static const int root = Mid; 
       };
      
     template <int Size, int Low, int High>          
       struct Root {
           static const int mean = (Low + High)/2;
           static const bool down = (mean * mean >= Size);
           static const int root = Root<Size, 
                  (down ? Low : mean+1), 
                  (down ? mean : High) >::root;     
       };                                                                  
      
     // User code:
     //   compute sqrt(N), use it for static table size                       

     int table[Root<N>::root];