Recursive data structure error in mex compiling of object-oriented program

Question

Chris Wolf 2016-3-4

3
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/271523-recursive-data-structure-error-in-mex-compiling-of-object-oriented-program

编辑： Dominik Müller 2020-11-10

I am attempting to use Matlab Coder to build a mex function. The function itself is the front end for an object oriented program. I'm getting a compiling error and can reproduce it with a simple toy example.

The following example compiles and executes without errors. It consists of three files: the main function, an example parent class, and an example child class:

    function str = main
        M = ParentClass;
        str = 'Done';
    end

...

 classdef ParentClass < handle
    properties
        Child;
    end
    methods
        function self = ParentClass
            self.Child = ChildClass;
        end
    end
 end

...

 classdef ChildClass < handle
    properties
    end
    methods
        function self = ChildClass
        end
    end    
 end

I'd like the child to keep a reference to its parent as a property, which is key for many design patterns. However, this causes a compiling error. I implement it by modifying the two classdefs as shown below. When the parent creates the child, the child stores the parent during the constructor.

 classdef ParentClass < handle
    properties
        Child;
    end
    methods
        function self = ParentClass
            self.Child = ChildClass(self);  % Line with the compiling error
        end
    end
 end

...

 classdef ChildClass < handle
    properties
        Parent
    end
    methods
        function self = ChildClass(Parent)
            self.Parent = Parent;
        end
    end    
 end

This produces the coder compiling error "This expression and its property 'Parent.Child' have the same class. Code generation does not support recursive data structures."

Is there a simple way around this language limitation? It works fine in the regular matlab environment, and this behavior is supported in other languages.

edit: Essentially, I'm looking for a way for the Child and Parent to have a reference to each other that is compatible with Matlab Coder.

Thanks in advance for the help