Add include of sstream header

diff --git a/src/thread_pool_observer.cpp b/src/thread_pool_observer.cpp
index 7c6f189..d630fd9 100644 (file)
--- a/src/thread_pool_observer.cpp
+++ b/src/thread_pool_observer.cpp
@@ -34,6 +34,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <stdio.h>
 
 #include <deque>
+#include <sstream>
 
 #include <yazpp/socket-observer.h>
 #include <yaz/log.h>