Make sure low and high have matching dtype. (So that `tfb.Sigmoid(low…

…=0., high=5)` works.)

PiperOrigin-RevId: 294926176

tensorflow_probability/python/bijectors/sigmoid.py

@@ -21,6 +21,7 @@
 import tensorflow.compat.v2 as tf
 from tensorflow_probability.python.bijectors import bijector
 from tensorflow_probability.python.internal import assert_util
+from tensorflow_probability.python.internal import dtype_util
 from tensorflow_probability.python.internal import tensor_util
 
 
@@ -74,8 +75,9 @@ def __init__(self, low=None, high=None, validate_args=False, name='sigmoid'):
             'Either both or neither of `low` and `high` must be passed. '
             'Received `low={}`, `high={}`'.format(low, high))
 
-      self._low = tensor_util.convert_nonref_to_tensor(low)
-      self._high = tensor_util.convert_nonref_to_tensor(high)
+      dtype = dtype_util.common_dtype([low, high], dtype_hint=tf.float32)
+      self._low = tensor_util.convert_nonref_to_tensor(low, dtype=dtype)
+      self._high = tensor_util.convert_nonref_to_tensor(high, dtype=dtype)
       super(Sigmoid, self).__init__(
           forward_min_event_ndims=0,
           validate_args=validate_args,