Limit circular ref check to list, tuple, dict

Author: dbaston

include/pybind11_json/pybind11_json.hpp

@@ -68,13 +68,16 @@ namespace pyjson
         }
     }
 
-    inline nl::json to_json(const py::handle& obj, std::set<const PyObject*>& refs)
+    inline void check_circular_ref(const py::handle& obj, std::set<const PyObject*>& refs)
     {
         auto insert_ret = refs.insert(obj.ptr());
         if (!insert_ret.second) {
             throw std::runtime_error("Circular reference detected");
         }
+    }
 
+    inline nl::json to_json(const py::handle& obj, std::set<const PyObject*>& refs)
+    {
         if (obj.ptr() == nullptr || obj.is_none())
         {
             return nullptr;
@@ -124,6 +127,7 @@ namespace pyjson
         }
         if (py::isinstance<py::tuple>(obj) || py::isinstance<py::list>(obj))
         {
+            check_circular_ref(obj, refs);
             auto out = nl::json::array();
             for (const py::handle value : obj)
             {
@@ -133,6 +137,7 @@ namespace pyjson
         }
         if (py::isinstance<py::dict>(obj))
         {
+            check_circular_ref(obj, refs);
             auto out = nl::json::object();
             for (const py::handle key : obj)
             {