From 7d0a1532a53036ad052ceb875c016d179e4285b5 Mon Sep 17 00:00:00 2001
From: Esteban Pavese <esteban.pavese@here.com>
Date: Tue, 3 Mar 2020 12:45:35 +0100
Subject: [PATCH] return value for insert() was inconsistent with std sets

---
 enumset/src/lib.rs   | 2 +-
 enumset/tests/ops.rs | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/enumset/src/lib.rs b/enumset/src/lib.rs
index 3be1cf0..66f605f 100644
--- a/enumset/src/lib.rs
+++ b/enumset/src/lib.rs
@@ -343,7 +343,7 @@ impl <T : EnumSetType> EnumSet<T> {
 
     /// Adds a value to this set.
     pub fn insert(&mut self, value: T) -> bool {
-        let contains = self.contains(value);
+        let contains = !self.contains(value);
         self.__enumset_underlying = self.__enumset_underlying | Self::mask(value.enum_into_u8());
         contains
     }
diff --git a/enumset/tests/ops.rs b/enumset/tests/ops.rs
index b6cfe2a..217ebd4 100644
--- a/enumset/tests/ops.rs
+++ b/enumset/tests/ops.rs
@@ -112,6 +112,15 @@ macro_rules! test_enum {
             assert!(set.is_empty());
         }
 
+        #[test]
+        fn already_present_element() {
+            let mut set = EnumSet::new();
+            assert!(set.insert($e::A));
+            assert!(!set.insert($e::A));
+            set.remove($e::A);
+            assert!(set.insert($e::A));
+        }
+
         #[test]
         fn empty_is_empty() {
             assert_eq!(EnumSet::<$e>::empty().len(), 0)
-- 
2.44.0