Merge sort c++

template <typename NekiTip>
void merge(NekiTip* niz, const int l, const int p, const int q, const int u) {
    int i(0), j(q-l), k(l);
    NekiTip* B = new NekiTip[u - l + 1];
    for( int m = 0; m <= u - l; m++)
        B[m] = niz[l + m];
    while(i <= p - l && j <= u - l) {
        if(B[i] < B[j])
            niz[k] = B[i++];
        else
            niz[k] = B[j++];
        k++;
    }
    while( i <= p - l) {
        niz[k] = B[i];
        k++;
        i++;
    }
    while( j <= u - l) {
        niz[k] = B[j];
        k++;
        j++;
    }
    delete [] B;
}