template specialization according to sizeof type

Question

I would like to provide a templated function, that varies its implementation (->specialization) according to the sizeof the template type.

Something similar to this (omi

Answer 1

Simply make an auxiliary class that takes the size as a template argument:

#include 
#include 


template
struct ByteSwapper { };

template<>
struct ByteSwapper<2> {
  static unsigned short swap(unsigned short a) {
    return 2 * a;
  }
};

template
T byteswap(const T& a) {
  return ByteSwapper::swap(a);
}


int main() {
  unsigned short s = 5;
  std::cout << byteswap(s) << std::endl;
  unsigned int i = 7;
  // std::cout << byteswap(i) << std::endl; // error
}