Simple version of metafunction that converts Binary to Decimal

binary.cpp

#include<iostream>
  

// Improved version of metafunction that convert 
// Binary to Decimal
// 
template<unsigned long N>
struct B_TO_D{
  static unsigned constexpr value = B_TO_D<N/10>::value << 1 | N%10; // prepend higher bits to lowest bit
};

template<>
struct B_TO_D<0>
{
  static unsigned constexpr value = 0;
};

int main(){
    auto decimal = B_TO_D<1010>::value;
    std::cout << decimal << std::endl;
}