SortedSet<T>.Trim extension

Assets/Mirror/Runtime/Extensions.cs

@@ -53,5 +53,16 @@ public static bool TryDequeue<T>(this Queue<T> source, out T element)
             return false;
         }
 #endif
+
+        // helper function to trim a set to a max length
+        public static void Trim<T>(this SortedSet<T> set, int maxLength)
+        {
+            // make sure we don't deadlock for negative length
+            if (maxLength < 0) return;
+
+            // remove while count > max
+            while (set.Count > maxLength)
+                set.Remove(set.Max);
+        }
     }
 }

Assets/Mirror/Tests/Editor/ExtensionsTest.cs

@@ -22,5 +22,31 @@ public void CopyToList()
             source.CopyTo(destination);
             Assert.That(destination.SequenceEqual(source), Is.True);
         }
+
+        [Test]
+        public void SortedSet_Trim()
+        {
+            SortedSet<int> set = new SortedSet<int>{1, 2, 3, 4, 5};
+
+            // larger than count
+            set.Trim(6);
+            Assert.That(set.SequenceEqual(new []{1, 2, 3, 4, 5}));
+
+            // exactly count
+            set.Trim(5);
+            Assert.That(set.SequenceEqual(new []{1, 2, 3, 4, 5}));
+
+            // smaller than count
+            set.Trim(3);
+            Assert.That(set.SequenceEqual(new []{1, 2, 3}));
+
+            // negative should not deadlock
+            set.Trim(-1);
+            Assert.That(set.SequenceEqual(new []{1, 2, 3}));
+
+            // zero
+            set.Trim(0);
+            Assert.That(set.SequenceEqual(new int[0]));
+        }
     }
 }