Add a trampoline to Node.add_child in order to set None default value to avoid...

Add a trampoline to Node.add_child in order to set None default value to avoid conversion of nullptr -> std::shared_ptr.

include/aidge/graph/Node.hpp

@@ -140,7 +140,7 @@ public:
 
   /**
    * @brief List of pair <Parent, ID of the data intput>. When an input is not
-   * linked to any Parent, the pair is <nullptr, gk_IODefaultIndex>. 
+   * linked to any Parent, the pair is <nullptr, gk_IODefaultIndex>.
    * Data inputs exclude inputs expecting parameters (weights or bias).
    * @return std::vector<std::pair<std::shared_ptr<Node>, IOIndex_t>>
    */

python_binding/graph/pybind_Node.cpp

@@ -63,12 +63,19 @@ void init_Node(py::module& m) {
     )mydelimiter")
 
     .def("add_child",
-        (void (Node::*)(std::shared_ptr<GraphView>, const IOIndex_t,
-                        std::pair<std::shared_ptr<Node>, IOIndex_t>)) &
-                Node::addChild,
+        [](Node &self, std::shared_ptr<GraphView> other_graph, const IOIndex_t out_id=0,
+                        py::object other_in_id = py::none()) {
+            std::pair<NodePtr, IOIndex_t> cpp_other_in_id;
+            // Note: default arg nullptr to allow python binding
+            if (other_in_id.is_none()) {
+                cpp_other_in_id = std::pair<NodePtr, IOIndex_t>(nullptr, gk_IODefaultIndex);
+            }else{
+                cpp_other_in_id = other_in_id.cast<std::pair<NodePtr, IOIndex_t>>();
+            }
+            self.addChild(other_graph, out_id, cpp_other_in_id);
+        },
         py::arg("other_graph"), py::arg("out_id") = 0,
-        py::arg("other_in_id") =
-                std::pair<std::shared_ptr<Node>, IOIndex_t>(nullptr, gk_IODefaultIndex),
+        py::arg("other_in_id") = py::none(),
                R"mydelimiter(
     Link a Node from a specific GraphView to the current Node.