classes with static (constant) properties
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How do I define static class properties that are accessed without allocating the object?
By object I mean class instance. I would just need constant properties (snippet below) but would also like to know how it would work for non-static properties too. I definetely prefer method 2 over 1 but calling foo.prop1 may create a temporary object tmp of class foo. In detail: The call of prop1 is the made via tmp. After the value of prop1 has been returned, the temporary object tmp is destroyed (deallocated). The described behavior would cause a small but significant load on performance/memory that can accumulate when one uses method 2 a lot or very often.
Method 1 has its own problems, where one is definitely that complicated construction of the member with a function and a persistant variable.
classdef foo
% METHOD 1:
% static function, defines local persistent var that is returned on each call
% Upside: definitely static, no object instantiation
% Downside: little overhead (function call, var is set every call)
% Rem. quest: Name of persistent var must be unique in whole workspace?
methods (Static)
function out = prop1()
persistent prop1_loc;
prop1_loc = 1;
out = prop1_loc;
end
end
% METHOD 2:
% Constant properties that can be accesses in the same manner as the static function
% Upside: Simple, shorter that method 1.
% Downside: None, unless the object is not instantiated by a call of foo.prop1
% Rem. quest: Does call to prop allocate an object (class instance)?
properties(Constant)
prop1 = 1;
prop2 = 2;
end
end
%%%%%%%% %%%%%%%%
%called like
x = foo.prop1;
func(foo.prop1);
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