Discover ignored output arguments from inside function?

[Judd Storrs]

Recently octave gained the ability to ignore output arguments. Is there currently any way to know whether a particular output is destined to be discarded from within the function? For example suppose:

function [a,b,c,d] = myfunc(e)

    a = ....

    b = ....

    c = ....

    d = ....

endfunction

If I call this like:

[a,~,~,d] = myfunc(e) 

is there any way for myfunc() to know not to put too much effort into computing b and c? I can think of plenty of inelegant kludges that commit the sins of verbosity, fragility and complexity. What I'm looking for is something direct and automatic like 

function [a,b,c,d] = myfunc(e)

   if isignored("b")

       b = ....

   endif

   if isignored(3)

       c = ....

   endif

   ...etc...

endfunction

--judd