diff -ur librealsense-2.7.9.orig/src/concurrency.h librealsense-2.7.9.include-functional/src/concurrency.h
--- librealsense-2.7.9.orig/src/concurrency.h	2017-09-17 15:18:56.000000000 +0200
+++ librealsense-2.7.9.include-functional/src/concurrency.h	2017-09-18 14:51:57.716452677 +0200
@@ -7,6 +7,7 @@
 #include <condition_variable>
 #include <thread>
 #include <atomic>
+#include <functional>
 
 const int QUEUE_MAX_SIZE = 10;
 // Simplest implementation of a blocking concurrent queue for thread messaging