fuseIndex_int32 Function

    pure function fuseIndex_int32(q, p) result(ind)
        ! fuse p,q into one symmetric index
        ! the resulting index is not contigious in p or q
        ! Input: p,q - 2d-array indices
        ! Output: ind - 1d-array index assuming the array is symmetric w.r. p<->q
        integer(int32), intent(in) :: p, q
        integer(int32) :: ind

        ! qp and pq are considered to be the same index
        ! -> permutational symmetry
        ! implemented in terms of fuseIndex_int64
        ind = int(fuseIndex_int64(int(q, int64), int(p, int64)))
    end function fuseIndex_int32