Compile-Time Log2

#define MATH_OP(n, exp) template<UINT a, UINT b> struct n { enum { value = (exp) }; }
#define LOG_OP(n, exp)  template<UINT x> struct n { enum { value = (exp) }; }

MATH_OP(And,         a & b);
MATH_OP(Add,         a + b);
MATH_OP(RSh,         a >> b);
MATH_OP(OrRSh,       a | (a >> b));
MATH_OP(AddRSh,      a + (a >> b));

LOG_OP(Log2Line01, (OrRSh<x, 1>::value));
LOG_OP(Log2Line02, (OrRSh<x, 2>::value));
LOG_OP(Log2Line03, (OrRSh<x, 4>::value));
LOG_OP(Log2Line04, (OrRSh<x, 8>::value));
LOG_OP(Log2Line05, (OrRSh<x, 16>::value));
LOG_OP(Log2Line06, (RSh<x, 1>::value));
LOG_OP(Log2Line07, (x - ((x >> 1) & 0x55555555)));
LOG_OP(Log2Line08, (((x >> 2) & 0x33333333) + (x & 0x33333333)));
LOG_OP(Log2Line09, (((x >> 4) + x) & 0x0f0f0f0f));
LOG_OP(Log2Line10, (AddRSh<x, 8>::value));
LOG_OP(Log2Line11, (AddRSh<x, 16>::value));
LOG_OP(Log2Line12, (x & 63));

template<UINT x> struct Log2Const
{
       enum
       {
              value =
                 Log2Line12<
                  Log2Line11<
                   Log2Line10<
                    Log2Line09<
                     Log2Line08<
                      Log2Line07<
                       Log2Line06<
                        Log2Line05<
                         Log2Line04<
                          Log2Line03<
                           Log2Line02<
                            Log2Line01<x>::value
                           >::value
                          >::value
                         >::value
                        >::value
                       >::value
                      >::value
                     >::value
                    >::value
                   >::value
                  >::value
                 >::value
       };
};