Want to create a function for each pin of the Arduino board using templates

So I'm working with pots and I want to smooth out the measurements. So I created a function that takes ten measurements and returns the average and I want to be able to call it the same way I would call analogRead(). So I created a template for this purpose, here's the code:

template<const uint8_t& PIN>
unsigned smoothReading(const uint8_t& PIN)
{
  static unsigned sample[10];
  static unsigned currentUnit = 0;


  if(currentUnit < 9) currentUnit++;
  else currentUnit = 0;

  sample[currentUnit] = analogRead(PIN);

  double average = 0;
  for (const auto& unit : sample)
    average += unit;
  
  average = average / 10;

  return round(average);
}

As you can see, I have some static variables which can't be shared among function calls for each pin. To be more precise, each pin has its own sample array of measurements, etc. So I have to either write this as a template; or have one single function and global variables for each pin I want to measure; or declare multiple versions of the function for each pin I want to measure. So I prefer just using a template.

The problem is, I keep getting shadows template parm errors. So,does the compiler think I'm trying to declare two different parameters with the same name? How can I make the template parameter resolve to the function parameter? Is there any other reason for this error?