module Numo
  class NArray
    def empty?: () -> bool
    def ndim: () -> Integer
    def shape: () -> Array[Integer]
    def swapaxes: (Integer, Integer) -> untyped
  end

  class DFloat < NArray
    def *: (untyped) -> untyped
    def []: (*untyped) -> untyped
    def []=: (*untyped) -> untyped
  end

  class DComplex < NArray
    def self.zeros: (*untyped) -> Numo::DComplex
    def *: (untyped) -> untyped
    def []: (*untyped) -> untyped
    def []=: (*untyped) -> untyped
    def real: () -> Numo::DFloat
  end
end