Merge pull request diffblue#146 from diffblue/nathan/feature/save-const-objects

Change json_serializer to allow saving const objects

Author: NathanJPhillips

src/util/json_serializer.h

@@ -232,12 +232,12 @@ class json_serializert:public serializert
   \*******************************************************************/
   template<typename T>
   static void save(
-    T &object,
+    const T &object,
     const char *file_path)
   {
     json_objectt json;
     json_serializert serializer(json, false);
-    object.serialize(serializer);
+    const_cast<T &>(object).serialize(serializer);
     save_json(json, file_path);
   }
 
@@ -258,14 +258,14 @@ class json_serializert:public serializert
   \*******************************************************************/
   template<typename T>
   static void save(
-    T &object,
+    const T &object,
     const char *file_path,
     std::shared_ptr<serializer_traitst> traits)
   {
     json_objectt json;
     json_serializert serializer(json, false);
     serializer.set_traits(traits);
-    object.serialize(serializer);
+    const_cast<T &>(object).serialize(serializer);
     save_json(json, file_path);
   }