From 28c80b87b8a65a20c4ab655c0f073cdf54353e0f Mon Sep 17 00:00:00 2001
From: Matvey Larionov <matthewtff@yandex-team.ru>
Date: Fri, 23 Oct 2015 14:27:08 +0300
Subject: [PATCH] Cached Object string representation

Calling toString on Object may cost a lot. It's much better to
have cached value for it.
---
 src/utils/isPlainObject.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/utils/isPlainObject.js b/src/utils/isPlainObject.js
index db3f6a0113..4a37a2aa2c 100644
--- a/src/utils/isPlainObject.js
+++ b/src/utils/isPlainObject.js
@@ -1,4 +1,5 @@
 var fnToString = (fn) => Function.prototype.toString.call(fn);
+var objStringValue = fnToString(Object);
 
 /**
  * @param {any} obj The object to inspect.
@@ -19,5 +20,5 @@ export default function isPlainObject(obj) {
 
   return typeof constructor === 'function'
     && constructor instanceof constructor
-    && fnToString(constructor) === fnToString(Object);
+    && fnToString(constructor) === objStringValue;
 }