--- BsonArray.cs.orig	2011-06-16 23:53:20.000000000 +0400
+++ BsonArray.cs	2011-06-25 01:46:38.419161300 +0400
@@ -29,7 +29,7 @@
     [Serializable]
     public class BsonArray : BsonValue, IComparable<BsonArray>, IEquatable<BsonArray>, IList<BsonValue> {
         #region private fields
-        private List<BsonValue> values = new List<BsonValue>();
+        private List<BsonValue> values;
         #endregion
 
         #region constructors
@@ -38,6 +38,16 @@
         /// </summary>
         public BsonArray()
             : base(BsonType.Array) {
+            values = new List<BsonValue>();
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the BsonArray class.
+        /// </summary>
+        /// <param name="capacity">Initial array capacity.</param>
+        public BsonArray(int capacity)
+            : base(BsonType.Array) {
+            values = new List<BsonValue>(capacity);
         }
 
         /// <summary>
@@ -377,11 +387,7 @@
         public BsonArray AddRange(
             IEnumerable<bool> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonBoolean.Create(value));
-                }
-            }
+            AddRange(values, BsonBoolean.Create);
             return this;
         }
 
@@ -393,6 +399,7 @@
         public BsonArray AddRange(
             IEnumerable<BsonValue> values
         ) {
+            Grow(0);
             if (values != null) {
                 this.values.AddRange(values);
             }
@@ -407,11 +414,7 @@
         public BsonArray AddRange(
             IEnumerable<DateTime> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonDateTime.Create(value));
-                }
-            }
+            AddRange(values, BsonDateTime.Create);
             return this;
         }
 
@@ -423,11 +426,7 @@
         public BsonArray AddRange(
             IEnumerable<double> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonDouble.Create(value));
-                }
-            }
+            AddRange(values, BsonDouble.Create);
             return this;
         }
 
@@ -439,11 +438,7 @@
         public BsonArray AddRange(
             IEnumerable<int> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonInt32.Create(value));
-                }
-            }
+            AddRange(values, BsonInt32.Create);
             return this;
         }
 
@@ -455,11 +450,7 @@
         public BsonArray AddRange(
             IEnumerable<long> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonInt64.Create(value));
-                }
-            }
+            AddRange(values, BsonInt64.Create);
             return this;
         }
 
@@ -471,11 +462,7 @@
         public BsonArray AddRange(
             IEnumerable<object> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonValue.Create(value));
-                }
-            }
+            AddRange(values, BsonValue.Create);
             return this;
         }
 
@@ -487,11 +474,7 @@
         public BsonArray AddRange(
             IEnumerable<ObjectId> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonObjectId.Create(value));
-                }
-            }
+            AddRange(values, BsonObjectId.Create);
             return this;
         }
 
@@ -503,11 +486,7 @@
         public BsonArray AddRange(
             IEnumerable<string> values
         ) {
-            if (values != null) {
-                foreach (var value in values) {
-                    this.values.Add(BsonString.Create(value));
-                }
-            }
+            AddRange(values, BsonString.Create);
             return this;
         }
 
@@ -516,9 +495,10 @@
         /// </summary>
         /// <returns>A shallow clone of the array.</returns>
         public override BsonValue Clone() {
-            BsonArray clone = new BsonArray();
-            foreach (var value in values) {
-                clone.Add(value.Clone());
+            int count = values.Count;
+            BsonArray clone = new BsonArray(count);
+            for (int i = 0; i < count; i++) {
+                clone.Add(values[i].Clone());
             }
             return clone;
         }
@@ -606,9 +586,10 @@
         /// </summary>
         /// <returns>A deep clone of the array.</returns>
         public override BsonValue DeepClone() {
-            BsonArray clone = new BsonArray();
-            foreach (var value in values) {
-                clone.Add(value.DeepClone());
+            int count = values.Count;
+            BsonArray clone = new BsonArray(count);
+            for (int i = 0; i < count; i++) {
+                clone.Add(values[i].DeepClone());
             }
             return clone;
         }
@@ -780,6 +761,48 @@
         IEnumerator IEnumerable.GetEnumerator() {
             return GetEnumerator();
         }
+
+        void Grow(int count) {
+            if (this.values != null) {
+                int capacity = this.values.Count + count;
+                if (this.values.Capacity < capacity)
+                    this.values.Capacity = capacity;
+            }
+            else
+                this.values = new List<BsonValue>(count);
+        }
+
+        void AddRange<T>(IEnumerable<T> values, Func<T, BsonValue> transform) {
+            if (values == null) {
+                Grow(0);
+                return;
+            }
+            var valuesArray = values as T[];
+            if (valuesArray != null) {
+                int count = valuesArray.Length;
+                Grow(count);
+                for (int i = 0; i < count; i++)
+                    this.values.Add(transform(valuesArray[i]));
+            }
+            else {
+                var valuesList = values as IList<T>;
+                if (valuesList != null) {
+                    int count = valuesList.Count;
+                    Grow(count);
+                    for (int i = 0; i < count; i++)
+                        this.values.Add(transform(valuesList[i]));
+                }
+                else {
+                    var vc = values as ICollection;
+                    if (vc != null)
+                        Grow(vc.Count);
+                    else
+                        Grow(0);
+                    foreach (var value in values)
+                        this.values.Add(transform(value));
+                }
+            }
+        }
         #endregion
 
         #region explicit interface implementations