rust-index: simplification in find_gca_candidates()
`parent_seen` can be made a mutable ref, making this part more obvious,
not needing to be commented so much.
The micro-optimization of avoiding the union if `parent_seen` and
`current_seen` agree is pushed down in the `union()` method of the
fast, `u64` based bit set implementation (in case it matters).
# typelib.py - type hint aliases and support
#
# Copyright 2022 Matt Harbison <matt_harbison@yahoo.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import typing
# Note: this is slightly different from pycompat.TYPE_CHECKING, as using
# pycompat causes the BinaryIO_Proxy type to be resolved to ``object`` when
# used as the base class during a pytype run.
TYPE_CHECKING = typing.TYPE_CHECKING
# The BinaryIO class provides empty methods, which at runtime means that
# ``__getattr__`` on the proxy classes won't get called for the methods that
# should delegate to the internal object. So to avoid runtime changes because
# of the required typing inheritance, just use BinaryIO when typechecking, and
# ``object`` otherwise.
if TYPE_CHECKING:
from typing import (
BinaryIO,
)
BinaryIO_Proxy = BinaryIO
else:
BinaryIO_Proxy = object