use C++ way of #including C headers in SWIG bindings

diff --git a/tclpkg/gv/gv.cpp b/tclpkg/gv/gv.cpp
index d9f6844f87c6c44105dbae7b0e74526197d2da75..cb00a55d588c9cba847d035bf743f28aea25169f 100644 (file)
--- a/tclpkg/gv/gv.cpp
+++ b/tclpkg/gv/gv.cpp
@@ -8,8 +8,8 @@
  * Contributors: Details at https://graphviz.org
  *************************************************************************/
 
-#include <string.h>
-#include <stdlib.h>
+#include <cstring>
+#include <cstdlib>
 #include <gvc/gvc.h>
 #include <string>