The property 'someprop' restriction defined in class 'myobj2_class' must match the property definition in base class 'myobj1_class'.

Question

Igor Varfolomeev 2016-3-29

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/275979-the-property-someprop-restriction-defined-in-class-myobj2_class-must-match-the-property-definiti

编辑： Igor Varfolomeev 2016-3-29

Does anyone think that it would be nice to modify the behavior of the "Restrict Property Values to Specific Classes" feature, to allow the following use case:

"myprop1_class.m":

    classdef myprop1_class
    end

"myprop2_class.m":

    classdef myprop2_class < myprop1_class     
    end

"myobj1_class.m":

classdef myobj1_class 
    properties (Abstract)
        someprop@myprop1_class
    end
end

"myobj2_class.m":

classdef myobj2_class < myobj1_class    
    properties
        someprop@myprop2_class
    end  
end

"test_inheritance.m":

myobj = myobj2_class();
% R2016a says:
%
% Error using myobj2_class The property 'someprop' restriction defined in
% class 'myobj2_class' must match the property definition in base class
% 'myobj1_class'.
% 
% Error in test_inheritance (line 3)
% myobj = myobj2_class();
%
%
% That's a pity.
% I wished such a syntax would be allowed....

For me, such a change looks very nice. It perfectly matches the principle, that an object “myobj2” of a class “MyClass2”, inherited from “MyClass1”, perfectly passes the “isa(myobj2,MyClass1)” check, just like in case of this new “Restrict Property Values to Specific Classes” syntax.

Moreover, note, that this check could not be implemented with a custom set(..) method for myobj1_class, cause Matlab does not allow to implement set methods for Abstract properties.