From c6a873617153984d904eb0c83fd226ae10bfec86 Mon Sep 17 00:00:00 2001
From: Masamitsu MURASE <masamitsu.murase@gmail.com>
Date: Sun, 30 Nov 2014 03:36:23 +0900
Subject: [PATCH] Use string::compare to improve performance.

---
 json11.cpp | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/json11.cpp b/json11.cpp
index 6424554..88e376b 100644
--- a/json11.cpp
+++ b/json11.cpp
@@ -547,12 +547,11 @@ struct JsonParser {
     Json expect(const string &expected, Json res) {
         assert(i != 0);
         i--;
-        const string found = str.substr(i, expected.length());
-        if (expected == found) {
+        if (str.compare(i, expected.length(), expected) == 0) {
             i += expected.length();
             return res;
         } else {
-            return fail("parse error: expected " + expected + ", got " + found);
+            return fail("parse error: expected " + expected + ", got " + str.substr(i, expected.length()));
         }
     }