From e08d1f752462260837445399626bba3b09f31f75 Mon Sep 17 00:00:00 2001
From: Jon Hanna <jon@hackcraft.net>
Date: Wed, 4 Jan 2017 15:01:48 +0000
Subject: [PATCH] Optimise ToArray for list source

---
 Src/Newtonsoft.Json/Utilities/LinqBridge.cs | 26 ++++++++++++++-------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/Src/Newtonsoft.Json/Utilities/LinqBridge.cs b/Src/Newtonsoft.Json/Utilities/LinqBridge.cs
index 2777b418..f2327289 100644
--- a/Src/Newtonsoft.Json/Utilities/LinqBridge.cs
+++ b/Src/Newtonsoft.Json/Utilities/LinqBridge.cs
@@ -793,17 +793,25 @@ namespace Newtonsoft.Json.Utilities.LinqBridge
       return new List<TSource>(source);
     }
 
-    /// <summary>
-    /// Creates an array from an <see cref="IEnumerable{T}"/>.
-    /// </summary>
+      /// <summary>
+      /// Creates an array from an <see cref="IEnumerable{T}"/>.
+      /// </summary>
 
-    public static TSource[] ToArray<TSource>(
-      this IEnumerable<TSource> source)
-    {
-      return source.ToList().ToArray();
-    }
+      public static TSource[] ToArray<TSource>(
+        this IEnumerable<TSource> source)
+      {
+          IList<TSource> ilist = source as IList<TSource>;
+          if (ilist != null)
+          {
+              TSource[] array = new TSource[ilist.Count];
+              ilist.CopyTo(array, 0);
+              return array;
+          }
 
-    /// <summary>
+          return source.ToList().ToArray();
+      }
+
+      /// <summary>
     /// Returns distinct elements from a sequence by using the default 
     /// equality comparer to compare values.
     /// </summary>