Handle class via mwArray in C++

Hello,

i am using Matlab code (compiled to a .dll) that creates an object of a handle class. Methods of the Object can be called by using the .dll interface functions. However, methods are not called directly but by using "wrapper functions" which accept a HANDLE to the MATLAB object as input.

The methods can be called directly in MATLAB and as described "indirectly" from C++, but they return different results when i call them from C++.

What can be the cause for such behaviour?

I would be glad to have any hint, why MATLAB code can behave different when called through a .dll.

Thanks a lot,

Ulrich

[Ulrich]

Example below:

classdef handleExample < handle
    % ....
    
    
   methods 
       
       function obj = handleExample(input)
           
           % create Obj
           
       end
       
       function obj = doSomeThing(obj, input)
       
       % ... lots of things
       %
       end
   end
end

The constructor is then called in function which returns this "Handle":

function hOut = mwConstructor()

    % ... 
    input = struct( 'a lot of fields', '');
    
    hOut = handleExample(input);
    
    return;
   
end

This function is added to the .dll exported functions as well as a wrapper:

function ret = wrapper(hObj, input)

    %
    hObj = doSomeThing(hObj, input)
    ret = hObj.special_field;
    return;

end

The wrapper is then called cyclic by a C++ application that makes use of the .dll that was generated by the MATLAB compiler.

But the results of "doSomeThings" seem to differ not just slightly, but in a really crazy way.