Accessing Elements of an output of an extrinsic call

I am trying to assign to output of an extrinsic call. I know I have to initialize it prior to the extrinsic call. In my case the extrinsic function returns an object. I tried to pre-initialize with a structure similar to that object.

        coder.extrinsic('operspec');
        op=StructOpspec(); % Constructing a structure with the same feilds and types of operspec output;
        op = operspec(plant_mdl);

But it complains: "MATLAB expression 'operspec' is not of the correct class: expected 'struct', found 'opcond.OperatingSpec'

Answer 1

[madhan ravi]

might help:

https://www.mathworks.com/matlabcentral/answers/122167-subscripting-into-an-mxarray-is-not-supported#answer_129328