unbreak build

Test Plan: built producer_consumer_queue_test with gcc 4.7.1
@override-unit-failures

Reviewed By: chip@fb.com

FB internal diff: D942465

diff --git a/folly/ProducerConsumerQueue.h b/folly/ProducerConsumerQueue.h
index 3660c24718f73fcdbe3f38913d807fc224f5b02d..2a6ed376fc37a2eb5cd9ce1ab4799d067e840c95 100644 (file)
--- a/folly/ProducerConsumerQueue.h
+++ b/folly/ProducerConsumerQueue.h
@@ -27,6 +27,7 @@
 #include <type_traits>
 #include <utility>
 #include <boost/noncopyable.hpp>
+#include <boost/type_traits.hpp>
 
 namespace folly {