Fix OperatorTensor::forwardDims() if OptionalData is not connected.

python_binding/operator/pybind_OperatorTensor.cpp

@@ -33,6 +33,7 @@ void init_OperatorTensor(py::module& m){
     .def("set_output", (void (OperatorTensor::*)(const IOIndex_t, const std::shared_ptr<Data>&) const) &OperatorTensor::setOutput, py::arg("outputIdx"), py::arg("data"))
     .def("set_input", (void (OperatorTensor::*)(const IOIndex_t, const std::shared_ptr<Data>&)) &OperatorTensor::setInput, py::arg("outputIdx"), py::arg("data"))
     .def("forward_dims", &OperatorTensor::forwardDims, py::arg("allow_data_dependency") = false)
+    .def("forward_dtype", &OperatorTensor::forwardDType)
     .def("dims_forwarded", &OperatorTensor::dimsForwarded)
     ;
 }

src/operator/OperatorTensor.cpp

@@ -181,6 +181,12 @@ bool Aidge::OperatorTensor::forwardDType(){
                 // Param input can be different dtype than data input
                 continue;
             }
+            if (inputCategory(i) == InputCategory::OptionalData
+            && !getInput(i)){
+                // If OptionalData is not set, skip
+                continue;
+            }
+
             if (expectedDType != getInput(i)->dataType()) {
                 Log::info("{} operator's inputs should have the same datatype: expected {} (input #0), given {} (input #{})",
                     type(), expectedDType, getInput(i)->dataType(), i);