set_integer_int64 Function

    pure function set_integer_int64 (V) result(res)
        integer (int64), intent(in) :: V(:)
        integer(int64), allocatable :: res(:)
        integer(int64) :: sorted(size(V)), previous
        type(buffer_int64_1D_t) :: buffer
        integer :: i

        sorted = V
        call sort(sorted)

        call buffer%init()
        if (size(sorted) > 0) then
            call buffer%push_back(sorted(1))
            previous = sorted(1)
        end if
        do i = 2, size(sorted)
            if (previous /= sorted(i)) then
                call buffer%push_back(sorted(i))
                previous = sorted(i)
            end if
        end do
        call buffer%dump_reset(res)
    end function set_integer_int64