In a writable folder, create a System object, AddOne, which subclasses from matlab.System. Save the code as AddOne.m.

classdef AddOne < matlab.System
% ADDONE Compute an output value that increments the input by one

  methods (Access=protected)
    % stepImpl method is called by the step method
    function y = stepImpl(~,x)
      y = x+1;
    end
  end
end	  

Write a function that uses this System object.

function y = testAddOne(x)
%#codegen
  p = AddOne();
  y = p.step(x);
end    

Generate a MEX function for this code.

codegen -report testAddOne -args {0}

The -report option instructs codegen to generate a code generation report, even if no errors or warnings occur. The -args option specifies that the testAddOne function takes one scalar double input.

Click the View report link.

In the MATLAB Source pane, click testAddOne. To see information about the variables in testAddOne, click the Variables tab.

To view the class definition for addOne, in the MATLAB Source pane, click AddOne.