Added comment for traverse_py_cb_ro_impl

Author: DoeringChristian

src/python/detail.cpp

@@ -300,6 +300,13 @@ struct recursion_guard {
 };
 } // namespace
 
+/**
+ * \brief Traverses all variables of a python object.
+ *
+ * This function is used to traverse variables of python objects, inheriting
+ * from trampoline classes. This allows the user to freeze for example custom
+ * BSDFs, without having to declare its variables.
+ */
 void traverse_py_cb_ro_impl(nb::handle self, nb::callable c) {
     recursion_guard guard;
 
@@ -340,6 +347,13 @@ void traverse_py_cb_ro_impl(nb::handle self, nb::callable c) {
     }
 }
 
+/**
+ * \brief Traverses all variables of a python object.
+ *
+ * This function is used to traverse variables of python objects, inheriting
+ * from trampoline classes. This allows the user to freeze for example custom
+ * BSDFs, without having to declare its variables.
+ */
 void traverse_py_cb_rw_impl(nb::handle self, nb::callable c) {
     recursion_guard guard;
 

tests/call_ext.cpp

@@ -20,9 +20,9 @@ struct Sampler : dr::TraversableBase {
 
     T next() { return rng.next_float32(); }
 
-    DR_TRAVERSE_CB(dr::TraversableBase, rng);
-
     dr::PCG32<dr::uint64_array_t<T>> rng;
+
+    DR_TRAVERSE_CB(dr::TraversableBase, rng);
 };
 
 template <typename Float> struct Base : drjit::TraversableBase {