Специализация шаблонов функций

template <typename T>
T max_elem(const T *arr, int c) {
    T max = arr[0];
    for (int i = 1;i<c;i++)
        if (arr[i] > max) max = arr[i];
    return max;
}
 
template <> double max_elem(const double *arr, int c) {
    double max = arr[0];
    for (int i = 1;i<c;i++)
        if (arr[i] > max) max = arr[i];
    return -max;
}
 
template <> char * max_elem(const char **arr, int c) {
//  cout << arr[0] << endl;
//  cout << arr[1] << endl;
//  return NULL;
}

    int vi[6] = {-55,33,0,81,22,11};
    double vd[4] = {33,14.4,-3.8,0};
    const char *vs[5] = {"line one","line two","line three","line four","line five"};
    
    cout << "int: " << max_elem(vi,6) << endl;
    cout << "double: " << max_elem(vd,4) << endl;
    cout << "char: " << max_elem(vs,5) << endl;

template <typename T>
T max_elem(const T *arr, int c) { ... }

template <> double max_elem(const double *arr, int c) { ... }

template <> const char * max_elem(const char **arr, int c) {

template <typename T>
T * max_elem(const T **arr, int c);

template <> char* max_elem( char * const  * arr, int c);

template <> 
char* max_elem(char* const* arr, int c)  {  ... }

char* const* arr