How to check if output argument is ignored?

Is is possible to check if a function gets called with to-be-ignored output arguments (using ~)?

function [Y1, Y2] = MyFunction(...)
% common code for Y1 and Y2 here
if //insert_check_here//
   % avoid this code when called as [~, B] = MyFunction (...)
end

For all these situations below, however, nargout returns 2, so that function seems to have no use in solving my problem.

[~,b] = myFunction
[a,~] = myFunction
[~,~] = myFunction % you may think about the usefulness of this call :)

Thanks! ~ Jos

Answer 1

[Stephen23]

No, it is currently not possible without writing some hack with dbstack and parsing the calling file. See also:

https://www.mathworks.com/matlabcentral/answers/184617-how-to-detect-in-output-argument-list-so-as-to-avoid-memory-allocation-inside-called-function

https://www.mathworks.com/matlabcentral/answers/142733-equivalent-of-inputname-for-output-variables

[Jos (10584)]

bummer ...

Thanks for the links!

[Stephen23]

I don't see that this would break any functionality, or be inconsistent with any other syntaxes: you should put in a feature request.

[Jos (10584)]

Done!

Adding an input to nargout would do: nargout(N) returning true if the N-th output argument is present and not ignored ... Without input argument, no change in behaviour. Plain and simple, without functionality loss, I think :D

[Ulf Ranggård]

It's now 2022, apparently this suggestion was not implemented?

Are there now any other standard way to detect the callers use of ~ ?