Simple implementation of Insertion Sort algorithm in C++

InsertionSort.cpp

// Fill an array with random numbers
template <typename Comparable>
void fillRandom(vector<Comparable> &iArray, Comparable range)
{
 srand((unsigned)time(0));
 for(Comparable i = 0; i < iArray.size(); i++)
 {
  iArray[i] = rand() % range;
 }
}

// Insertion Sort Forwards
template <typename Comparable>
void insertionSort(vector<Comparable> &a)
{
 for(int unsorted = 1; unsorted < a.size(); unsorted++)
 {
  int loc;
  Comparable nextItem = a[unsorted];
  for(loc = unsorted; loc > 0 && nextItem < a[loc - 1]; loc--)
  {
   a[loc] = a[loc - 1];
  }
 
  a[loc] = nextItem;
 }
}

// Insertion Sort Backwards
template <typename Comparable>
void insertionSortInverted(vector<Comparable> &a)
{
 for(int unsorted = a.size() - 2; unsorted >= 0; unsorted--)
 {
  int loc;
  Comparable nextItem = a[unsorted];
  for(loc = unsorted; loc < a.size() - 1 && nextItem > a[loc + 1]; loc++)
  {
   a[loc] = a[loc + 1];
  }
 
  a[loc] = nextItem;
 }
}