Add missing <iostream> header include

This will be required for subsequent commits that remove inclusion of
<iostream> from some shared headers.

diff --git a/libs/gtkmm2ext/utils.cc b/libs/gtkmm2ext/utils.cc
index c10497a8fbc847f21772357b157b69114c80ea7d..147256b426597fe3719e2c8587148d174d987d6c 100644 (file)
--- a/libs/gtkmm2ext/utils.cc
+++ b/libs/gtkmm2ext/utils.cc
@@ -20,6 +20,7 @@
 
 #include <map>
 #include <algorithm>
+#include <iostream>
 
 #include <gtk/gtkpaned.h>
 #include <gtk/gtk.h>