detectOutputSuppres​sion

Identify which function outputs have been suppressed by the caller using the tilde operators.

When a function is called with tilde operators in the outputs, those outputs are suppressed, even if the function computes their values.

Call detectOutputSuppression from within a function to detect which outputs have been suppressed by the caller.

ISTILDE= detectOutputSuppression(nargout)
Returns a logical vector identifying which outputs were suppressed by the caller using the tilde operators.
Matlab's nargout function is a required input and indicates the number of expected outputs.

[ISTILDE, CALLERTXT, CALLER, COMPONENTS] = detectOutputSuppression(nargout)
Returns additional information about the caller and the outputs it requested including the variable names.

detectOutputSuppression_tester() contains 84 examples that stress tests the detectOutputSuppression function using a wide variety of syntaxes and ensures the correct outputs and expected error messages are generated.

EXAMPLE
----------------------
function main()
[mst(1), ~, ~, data] = myFunc();

function [a, b, c, d] = myFunc()
a = 1; b = 2; c = 3; d = 4;
[ISTILDE, CALLERTXT, CALLER, COMPONENTS] = detectOutputSuppression(nargout)

Results:
ISTILDE = [0 1 1 0]
CALLERTXT = '[mst(1), ~, ~, data] = myFunc();'
CALLER is the caller stack info.
COMPONENTS contains information about the output names used by the caller.

See help('detectOutputSuppression') for a list of requirements and restrictions.

* Note that there are cleaner alternatives to this function.
1. Add an input to your function that specifies which outputs are requested.
2. Prioritize the function outputs.

Tested and fully functional in Matlab r2014a, 16a, 16b, 17b, 19b, and r2020a.