col_constructor_alloc_complex Subroutine

    subroutine col_constructor_alloc_complex(this, n)
        class(column), intent(inout) :: this
        integer, intent(in) :: n

        if (this % initialized) call this % destroy()
        this % initialized = .true.

        this % dtype = COMPLEX_NUM
        this % n = n
        allocate (this % ccol(n))

    end subroutine col_constructor_alloc_complex