From 972d93a95ec8b37fab84400417070b7439414967 Mon Sep 17 00:00:00 2001
From: Ram Rachum <ram@rachum.com>
Date: Mon, 16 Dec 2019 12:22:45 +0200
Subject: [PATCH] Optimized containment check in ChoicesMeta.

---
 django/db/models/enums.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/django/db/models/enums.py b/django/db/models/enums.py
index ae20ef6d93..f48143ddaf 100644
--- a/django/db/models/enums.py
+++ b/django/db/models/enums.py
@@ -36,7 +36,7 @@ class ChoicesMeta(enum.EnumMeta):
     def __contains__(cls, member):
         if not isinstance(member, enum.Enum):
             # Allow non-enums to match against member values.
-            return member in {x.value for x in cls}
+            return any(x.value == member for x in cls)
         return super().__contains__(member)
 
     @property