How to cast a subclass object to its superclass type..?

Hi everyone,

The MATLAB documentation states:

"MATLAB does not allow you to create arrays containing a mix of superclass and subclass objects because an array can be of only one class."

The MATLAB documentation for function cast() states:

"B = cast(A, newclass) converts A to class newclass, where newclass is the name of a built-in data type compatible with A."

Since we can't use the cast() function to convert a subclass to its superclass, how else can we perform the necessary conversion, in this or any general context..?

For example:

classdef MySuperClass
...
end

classdef MySubClass < MySuperClass
...
end

% Create subclass object:
mySubClassObj = MySubClass(..);

% Try to cast to superclass:
mySubClassObj = cast(mySubClassObj,'MySuperClass');
Error using cast
Unsupported class for conversion.

Any guidance / suggestions appreciated,

Thanks, Brad

Answer 1

[Daniel Shub]

First, since r2011a MATLAB supports "Heterogeneous Arrays":

http://www.mathworks.com/help/releases/R2011a/techdoc/ref/brk7uzk.html#bsvqsj1

You can also essentially do what cast does by defining your own conversion method:

http://www.mathworks.com/help/releases/R2011a/techdoc/matlab_oop/br2vkky.html

[Bradley Stiritz]

Hi Daniel, thanks very much for digging out these DOC pages for me, very appreciated :)

brad