I believe the following piece of code is a good replacement using the "memmove" function.

#include <string.h>
 
template <class T>
void insertionSort(T* a, int size)
{
  for (int i = 1; i < size; i++)
    if (a[i] < a[i - 1])
    {
      T temp = a[i];
      int j = i;
      while (--j && temp < a[j - 1]);
      memmove(a + j + 1, a + j, (i - j)*sizeof(T));
      a[j] = temp;
    }
}

So an example of how to use this function could be:

#include <string.h>
#include <stdio.h>
 
template <class T>
void insertionSort(T* a, int size)
{
  for (int i = 1; i < size; i++)
    if (a[i] < a[i - 1])
    {
      T temp = a[i];
      int j = i;
      while (--j && temp < a[j - 1]);
      memmove(a + j + 1, a + j, (i - j)*sizeof(T));
      a[j] = temp;
    }
}
 
int main()
{
  int a[6] = {100, 0, 1, -5, -10, -4};
 
  insertionSort<int>(a, 6);
  for (int i = 0; i < 6; i++)
    printf("%d ", a[i]);
  printf("\n\n");
 
  return 0;
}

I hope this helps.