Как работает этот код, создание цикла For?

template <unsigned long t> struct Polynome  { static const unsigned long value = t&1 ? (t>>1)^0xedb88320 : t>>1   }; };
template <unsigned long t, int i> struct For { static const unsigned long value = For<Polynome<t>::value, i-1 >::value; };
template <unsigned long t> struct For<t,0>  { static const unsigned long value = Polynome<t>::value;         };
template < unsigned long t> struct Hash    { static const unsigned long value = For<t,7>::value;           };
template<int r, int t> struct Table : Table<r+1, t-1>
{
  Table() { values[t]=Hash<t>::value; }
};
template<int r> struct Table<r,0>
{
  unsigned long values[r+1];
  Table() { values[0]=Hash<0>::value; }
  unsigned long operator[](int i) {  return values[i];}
};

static constexpr uint32_t crc32_elem(int i, uint32_t poly)
{
    uint32_t t = i;
    for (int j = 8; j > 0; --j) 
    {
        t = t & 1 ? (t >> 1) ^ 0xedb88320 : (t >> 1);
    }
    return t;    
}
template <std::size_t... I>
static constexpr std::array<uint32_t, sizeof...(I)> make_crc32_array(std::index_sequence<I...>, uint32_t poly)
{
    return { crc32_elem(I, poly)... };
}
static constexpr std::array<uint32_t, 256> crc32_init(uint32_t poly)
{
    return make_crc32_array(std::make_index_sequence<256>{}, poly);
}
 
constexpr std::array<uint32_t, 256> crc32table{ crc32_init(0xEDB88320) };

#include <array>
#include <cstdint>
#include <cstdio>
//----------- Utility ---------
template <size_t ...I>
struct indices
{ };
 
template <size_t Max, size_t ...Indices>
struct make_indices
    : make_indices<Max - 1, Max - 1, Indices...>
{ };
 
template <size_t ...Indices>
struct make_indices<0, Indices...>
    : indices<Indices...>
{
    using type = indices<Indices...>;
};
//-----------------------------
static constexpr uint32_t crc32_elem(uint32_t t, uint32_t poly, int j = 8)
{
    return j > 0 ? crc32_elem(t & 1 ? (t >> 1) ^ poly : (t >> 1), poly, --j) : t;
}
template <size_t... I>
static constexpr std::array<uint32_t, sizeof...(I)> make_crc32_array(indices<I...>, uint32_t poly)
{
    return std::array<uint32_t, sizeof...(I)>{ crc32_elem(I, poly)... };
}
static constexpr std::array<uint32_t, 256> crc32_init(uint32_t poly)
{
    return make_crc32_array(make_indices<256>{}, poly);
}

template <unsigned long t> struct Polynome  { static const unsigned long value = t&1 ? (t>>1)^0xedb88320 : t>>1   }; 
template <unsigned long t, int i> struct For { static const unsigned long value = For<Polynome<t>::value, i-1 >::value;