//  [python]
def test_infer_shape(self, cast_policy):
        with config.change_flags(cast_policy=cast_policy):
            start, stop, step = iscalars("start", "stop", "step")
            out = arange(start, stop, step)
            mode = config.mode
            if mode == "FAST_COMPILE":
                mode = "FAST_RUN"
            mode = compile.mode.get_mode(mode).excluding("fusion")
            f = function([start, stop, step], out.shape, mode=mode)
            assert len(f.maker.fgraph.toposort()) == 9

            if config.cast_policy == "custom":
                assert out.dtype == "int64"
            elif config.cast_policy == "numpy+floatX":
                numpy_dtype = np.arange(
                    np.array(0, dtype=start.dtype),
                    np.array(1, dtype=stop.dtype),
                    np.array(1, dtype=step.dtype),
                ).dtype
                assert out.dtype == numpy_dtype

            assert n.all(f(0, 5, 1) == len(np.arange(0, 5, 1)))
            assert n.all(f(2, 11, 4) == len(np.arange(2, 11, 4)))
            assert n.all(f(-5, 1, 1) == len(np.arange(-5, 1, 1)))
            assert n.all(f(10, 2, -2) == len(np.arange(10, 2, -2)))
            assert n.all(f(10, 2, 2) == len(np.arange(10, 2, 2)))
            assert n.all(f(0, 0, 1) == len(np.arange(0, 0, 1)))

            out = arange(start, stop, 1)
            f = function([start, stop], out.shape, mode=mode)
            assert len(f.maker.fgraph.toposort()) == 5
            # 4 [Elemwise{sub,no_inplace}(stop, start), Elemwise{Cast{int64}}(Elemwise{sub,no_inplace}.0), Elemwise{Maximum{output_types_preference=transfer_type{0}}}[(0, 0)](Elemwise{Cast{int64}}.0, 0), MakeVector(Elemwise{Maximum{output_types_preference=transfer_type{0}}}[(0, 0)].0)]
            if config.cast_policy == "custom":
                assert out.dtype == "int64"
            elif config.cast_policy == "numpy+floatX":
                assert (
                    out.dtype == np.arange(np.int32(0), np.int32(1), np.int32(1)).dtype
                )

            assert n.all(f(0, 5) == len(np.arange(0, 5)))
            assert n.all(f(2, 11) == len(np.arange(2, 11)))
            assert n.all(f(-5, 1) == len(np.arange(-5, 1)))
            assert n.all(f(10, 2) == len(np.arange(10, 2)))
            assert n.all(f(10, 2) == len(np.arange(10, 2)))
            assert n.all(f(0, 0) == len(np.arange(0, 0)))
            assert n.all(f(-64, 64) == len(np.arange(-64, 64)))
            assert arange(-64, 64).shape.eval() == [128]
            assert arange(-64, 64, 2).shape.eval() == [64]

            out = arange(0, stop, 1)
            f = function([stop], out.shape, mode=mode)
            assert len(f.maker.fgraph.toposort()) == 2
            # [Elemwise{Cast{int64}}(stop), MakeVector(Elemwise{Cast{int64}}.0)]

            if config.cast_policy == "custom":
                assert out.dtype == "int64"
            elif config.cast_policy == "numpy+floatX":
                numpy_dtype = np.arange(0, np.array(1, dtype=stop.dtype), 1).dtype
                assert out.dtype == numpy_dtype

            assert n.all(f(5) == len(np.arange(0, 5)))
            assert n.all(f(11) == len(np.arange(0, 11)))
            assert n.all(f(1) == len(np.arange(0, 1)))
            assert n.all(f(2) == len(np.arange(0, 2)))
            assert n.all(f(2) == len(np.arange(0, 2)))
            assert n.all(f(0) == len(np.arange(0, 0)))