Make Sigmoid registrable.

include/aidge/operator/Sigmoid.hpp

@@ -26,7 +26,7 @@
 namespace Aidge {
 
 class Sigmoid_Op : public OperatorTensor,
-    public Registrable<Sigmoid_Op, std::string, std::function<std::unique_ptr<OperatorImpl>(const Sigmoid_Op&)>> {
+    public Registrable<Sigmoid_Op, std::string, std::function<std::shared_ptr<OperatorImpl>(const Sigmoid_Op&)>> {
 public:
     static const std::string Type;
 
@@ -50,4 +50,4 @@ public:
 std::shared_ptr<Node> Sigmoid(const std::string& name = "");
 }
 
-#endif /* AIDGE_CORE_OPERATOR_SIGMOID_H_ */
+#endif /* AIDGE_CORE_OPERATOR_SIGMOID_H_ */
\ No newline at end of file

python_binding/operator/pybind_Sigmoid.cpp

@@ -25,6 +25,8 @@ void init_Sigmoid(py::module& m) {
     .def_static("get_outputs_name", &Sigmoid_Op::getOutputsName)
     .def_readonly_static("Type", &Sigmoid_Op::Type);
 
+    declare_registrable<Sigmoid_Op>(m, "SigmoidOp");
+
     m.def("Sigmoid", &Sigmoid, py::arg("name") = "");
 }
 }  // namespace Aidge