From 13a05e8671ec6b79d711822b6f16a16017653f08 Mon Sep 17 00:00:00 2001
From: Kai Ni <nikai97@gmail.com>
Date: Thu, 8 Apr 2010 22:16:08 +0000
Subject: [PATCH] add Ordering.exists

---
 cpp/Ordering.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/cpp/Ordering.h b/cpp/Ordering.h
index 0d7e54240..0fad87708 100644
--- a/cpp/Ordering.h
+++ b/cpp/Ordering.h
@@ -28,6 +28,9 @@ namespace gtsam {
 		/** Copy constructor */
 		Ordering(const std::list<Symbol>& keys_in) : std::list<Symbol>(keys_in) {}
 
+		/** whether a key exists */
+		bool exists(const Symbol& key) { return std::find(begin(), end(), key) != end(); }
+
 		// Testable
 		void print(const std::string& s = "Ordering") const;
 		bool equals(const Ordering &ord, double tol=0) const;