Cleanup more contextlib.AbstractContextManagers and Literal[False]s.

1 files changed, 5 insertions, 4 deletions

diff --git a/stopwatch.py b/stopwatch.py
index fa4f2b5..ae8e01a 100644
--- a/stopwatch.py
+++ b/stopwatch.py
@@ -2,11 +2,12 @@
 
 """A simple stopwatch decorator / context for timing things."""
 
+import contextlib
 import time
-from typing import Callable, Optional
+from typing import Callable, Literal
 
 
-class Timer(object):
+class Timer(contextlib.AbstractContextManager):
     """
     A stopwatch to time how long something takes (walltime).
 
@@ -31,6 +32,6 @@ class Timer(object):
         self.end = 0.0
         return lambda: self.end - self.start
 
-    def __exit__(self, *args) -> Optional[bool]:
+    def __exit__(self, *args) -> Literal[False]:
         self.end = time.perf_counter()
-        return None  # don't suppress exceptions
+        return False