-void gom_cast_error(char* file, int line, OBJ_TYPE expected, OBJ_TYPE found);
-void gom_no_context(char* file, int line);
-void gom_unexpected_context(char* file, int line, OBJ_TYPE found);
+void gom_cast_error(const char* file, int line,
+ OBJ_TYPE expected, OBJ_TYPE found);
+void gom_no_context(const char* file, int line);
+void gom_unexpected_context(const char* file, int line, OBJ_TYPE found);