diff --git a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/NotifyCollectionChangedEventArgs.cs b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/NotifyCollectionChangedEventArgs.cs
index a98194b..bb6b6c7 100644
--- a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/NotifyCollectionChangedEventArgs.cs
+++ b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/NotifyCollectionChangedEventArgs.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Specialized;
+using System.Runtime.InteropServices;
 
 namespace ObservableCollections
 {
@@ -17,6 +18,7 @@ namespace ObservableCollections
     ///     Action.Reset
     ///         -
     /// </summary>
+    [StructLayout(LayoutKind.Auto)]
     public readonly ref struct NotifyCollectionChangedEventArgs<T>
     {
         public readonly NotifyCollectionChangedAction Action;
diff --git a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/ObservableRingBuffer.cs b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/ObservableRingBuffer.cs
index 4bd8c81..3415f62 100644
--- a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/ObservableRingBuffer.cs
+++ b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/ObservableRingBuffer.cs
@@ -193,6 +193,30 @@ namespace ObservableCollections
             }
         }
 
+        public T[] ToArray()
+        {
+            lock (SyncRoot)
+            {
+                return buffer.ToArray();
+            }
+        }
+
+        public int BinarySearch(T item)
+        {
+            lock (SyncRoot)
+            {
+                return buffer.BinarySearch(item);
+            }
+        }
+
+        public int BinarySearch(T item, IComparer<T> comparer)
+        {
+            lock (SyncRoot)
+            {
+                return buffer.BinarySearch(item, comparer);
+            }
+        }
+
         public IEnumerator<T> GetEnumerator()
         {
             lock (SyncRoot)
diff --git a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/RingBuffer.cs b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/RingBuffer.cs
index 4adeb8d..2b71878 100644
--- a/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/RingBuffer.cs
+++ b/src/ObservableCollections.Unity/Assets/Plugins/ObservableCollections/Runtime/RingBuffer.cs
@@ -270,6 +270,35 @@ namespace ObservableCollections
             return result;
         }
 
+        public int BinarySearch(T item)
+        {
+            return BinarySearch(item, Comparer<T>.Default);
+        }
+
+        public int BinarySearch(T item, IComparer<T> comparer)
+        {
+            var lo = 0;
+            var hi = count - 1;
+
+            while (lo <= hi)
+            {
+                var mid = (int)(((uint)hi + (uint)lo) >> 1);
+                var found = comparer.Compare(this[mid], item);
+
+                if (found == 0) return mid;
+                if (found < 0)
+                {
+                    lo = mid + 1;
+                }
+                else
+                {
+                    hi = mid - 1;
+                }
+            }
+
+            return ~lo;
+        }
+
         void IList<T>.Insert(int index, T item)
         {
             throw new NotSupportedException();
diff --git a/src/ObservableCollections/NotifyCollectionChangedEventArgs.cs b/src/ObservableCollections/NotifyCollectionChangedEventArgs.cs
index 8353c81..9be0f6d 100644
--- a/src/ObservableCollections/NotifyCollectionChangedEventArgs.cs
+++ b/src/ObservableCollections/NotifyCollectionChangedEventArgs.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Specialized;
+using System.Runtime.InteropServices;
 
 namespace ObservableCollections
 {
@@ -17,6 +18,7 @@ namespace ObservableCollections
     ///     Action.Reset
     ///         -
     /// </summary>
+    [StructLayout(LayoutKind.Auto)]
     public readonly ref struct NotifyCollectionChangedEventArgs<T>
     {
         public readonly NotifyCollectionChangedAction Action;
diff --git a/src/ObservableCollections/ObservableRingBuffer.cs b/src/ObservableCollections/ObservableRingBuffer.cs
index fe4c8a4..3a92de2 100644
--- a/src/ObservableCollections/ObservableRingBuffer.cs
+++ b/src/ObservableCollections/ObservableRingBuffer.cs
@@ -193,6 +193,30 @@ namespace ObservableCollections
             }
         }
 
+        public T[] ToArray()
+        {
+            lock (SyncRoot)
+            {
+                return buffer.ToArray();
+            }
+        }
+
+        public int BinarySearch(T item)
+        {
+            lock (SyncRoot)
+            {
+                return buffer.BinarySearch(item);
+            }
+        }
+
+        public int BinarySearch(T item, IComparer<T> comparer)
+        {
+            lock (SyncRoot)
+            {
+                return buffer.BinarySearch(item, comparer);
+            }
+        }
+
         public IEnumerator<T> GetEnumerator()
         {
             lock (SyncRoot)
diff --git a/src/ObservableCollections/RingBuffer.cs b/src/ObservableCollections/RingBuffer.cs
index a4d24dd..f8ac262 100644
--- a/src/ObservableCollections/RingBuffer.cs
+++ b/src/ObservableCollections/RingBuffer.cs
@@ -270,6 +270,35 @@ namespace ObservableCollections
             return result;
         }
 
+        public int BinarySearch(T item)
+        {
+            return BinarySearch(item, Comparer<T>.Default);
+        }
+
+        public int BinarySearch(T item, IComparer<T> comparer)
+        {
+            var lo = 0;
+            var hi = count - 1;
+
+            while (lo <= hi)
+            {
+                var mid = (int)(((uint)hi + (uint)lo) >> 1);
+                var found = comparer.Compare(this[mid], item);
+
+                if (found == 0) return mid;
+                if (found < 0)
+                {
+                    lo = mid + 1;
+                }
+                else
+                {
+                    hi = mid - 1;
+                }
+            }
+
+            return ~lo;
+        }
+
         void IList<T>.Insert(int index, T item)
         {
             throw new NotSupportedException();
diff --git a/tests/ObservableCollections.Tests/RingBufferTest.cs b/tests/ObservableCollections.Tests/RingBufferTest.cs
index f8c4e52..7b137f2 100644
--- a/tests/ObservableCollections.Tests/RingBufferTest.cs
+++ b/tests/ObservableCollections.Tests/RingBufferTest.cs
@@ -124,6 +124,42 @@ namespace ObservableCollections.Tests
                 newArray.Should().Equal(0, 0, 199, 9, 999, 7, 6, 5, 1099, 4, 3, 888, 299, 0, 0);
             }
 
+        }
+
+        // TODO: need more test.
+        [Fact]
+        public void BinarySearchTest()
+        {
+            var empty = new RingBuffer<int>(new int[] { });
+            var single = new RingBuffer<int>(new[] { 10 });
+            var buffer = new RingBuffer<int>(new[]
+            {
+                1, 4, 5, 6, 10, 14, 15,17, 20, 33
+            });
+
+            empty.BinarySearch(99).Should().BeLessThan(0);
+
+            {
+                single.BinarySearch(10).Should().Be(0);
+                var x1 = single.BinarySearch(4);
+                x1.Should().BeLessThan(0);
+                (~x1).Should().Be(0);
+
+                var x2 = single.BinarySearch(40);
+                x2.Should().BeLessThan(0);
+                (~x2).Should().Be(1);
+            }
+
+            {
+                buffer.BinarySearch(0);
+
+
+            }
+
+
+
+
+
         }
     }
 }