Here is the page describing TensorFlow's tf.string_to_hash_bucket_fast. (Version is currently 1.3.) It says the file that defines this function is tensorflow/python/ops/gen_string_ops.py, which doesn't seem to exist on github. The gen might mean it's generated. Okay.
What is the solid definition of this function (i.e. so I could reimplement it if I wanted on another platform)?