[2185] Add include for NULL definition

diff --git a/src/lib/dns/rdata_pimpl_holder.h b/src/lib/dns/rdata_pimpl_holder.h
index 456440525d8217d0cb47667592c196c5c181cf14..2705dd854d75846f888547c725ae6e3e02f3893b 100644 (file)
--- a/src/lib/dns/rdata_pimpl_holder.h
+++ b/src/lib/dns/rdata_pimpl_holder.h
@@ -17,6 +17,8 @@
 
 #include <boost/noncopyable.hpp>
 
+#include <cstddef> // for NULL
+
 namespace isc {
 namespace dns {
 namespace rdata {