class_docstr: Tests specific to IntervalIndex with datetime-like subtype
class_docstr_tok: ["Tests","specific","to","IntervalIndex","with","datetime-like","subtype"]
code: def test_subtype_float(self, index):
      dtype = IntervalDtype("float64", "right")
      msg = "Cannot convert .* to .*; subtypes are incompatible"
      with pytest.raises(TypeError, match=msg):
          index.astype(dtype)
  
imports: import re
  import numpy
  import pytest
  from pandas.core.dtypes.dtypes import CategoricalDtype, IntervalDtype
  from pandas import CategoricalIndex, Index, IntervalIndex, NaT, Timedelta, Timestamp, interval_range
  import pandas._testing
label_desc: Use image node_id 3 for calling the TestDatetimelikeSubtype obj's underlying member method code with example usage: obj.test_subtype_float(index) without return types