Iwanngivethisagoodnamerightnow

template <class T>
void mergeSort(vector<T>& set, bool(*compare)(const T&, const T&))
{
        mergeSort(set, 0, set.size() - 1, compare);
}


template <class T>
void mergeSort(vector<T>& set, int low, int high, bool(*compare)(const T&, const T&))
{
        int mid;

        if (low < high)
        {
                mid = (low + high) / 2;

                //Divide and conquer

                mergeSort(set, low, mid, compare);
                mergeSort(set, mid + 1, high, compare);

                //Combine

                merge(set, low, mid, high, compare);
        }

}

template <class T>
void merge(vector<T>& set, int low, int mid, int high, bool(*compare)(const T&, const T&))
{
        vector<T> temp(high - low + 1);

        int i = low;
        int j = mid + 1;
        int k = 0;

        while (i <= mid && j <= high)
        {
                if (compare(set[j], set[i]))
                {
                        temp[k] = set[j];
                        ++j;
                        ++k;
                }
                else
                {
                        temp[k] = set[i];
                        ++i;
                        ++k;
                }
        }

        while (i <= mid)
        {
                temp[k] = set[i];
                ++i;
                ++k;
        }

        while (j <= high)
        {
                temp[k] = set[j];
                ++j;
                ++k;
    }

        for (i = 0, j = low; j <= high; i++, j++)
                set[j] = temp[i];

}