From a9890a75e6e539ca0d3678441ac5f9fd05345bd5 Mon Sep 17 00:00:00 2001
From: Sebastian Messmer <mail@smessmer.de>
Date: Wed, 10 Jun 2015 17:17:41 +0200
Subject: [PATCH] Fix for clang compiler

---
 optional_ownership_ptr.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/optional_ownership_ptr.h b/optional_ownership_ptr.h
index 5120c648..478e4461 100644
--- a/optional_ownership_ptr.h
+++ b/optional_ownership_ptr.h
@@ -3,6 +3,7 @@
 #define MESSMER_CPP_UTILS_OPTIONALOWNERSHIPPOINTER_H_
 
 #include <memory>
+#include <functional>
 
 /**
  * optional_ownership_ptr can be used to hold a pointer to an instance of an object.