1 files changed, 30 insertions, 0 deletions
diff --git a/django/utils/deprecation.py b/django/utils/deprecation.py
index 905bbc4f6d..70216e8c5b 100644
--- a/django/utils/deprecation.py
+++ b/django/utils/deprecation.py
@@ -79,3 +79,33 @@ class DeprecationInstanceCheck(type):
             self.deprecation_warning, 2
         )
         return super(DeprecationInstanceCheck, self).__instancecheck__(instance)
+
+
+class CallableBool:
+    """
+    An boolean-like object that is also callable for backwards compatibility.
+    """
+    do_not_call_in_templates = True
+
+    def __init__(self, value):
+        self.value = value
+
+    def __bool__(self):
+        return self.value
+
+    def __call__(self):
+        warnings.warn(
+            "Using user.is_authenticated() and user.is_anonymous() as a method "
+            "is deprecated. Remove the parentheses to use it as an attribute.",
+            RemovedInDjango20Warning, stacklevel=2
+        )
+        return self.value
+
+    def __nonzero__(self):  # Python 2 compatibility
+        return self.value
+
+    def __repr__(self):
+        return 'CallableBool(%r)' % self.value
+
+CallableFalse = CallableBool(False)
+CallableTrue = CallableBool(True)