Re: Can we deprecate/remove extra arguments currently accepted by numel?

[Andrew Janke]

On 3/15/19 12:34 AM, John W. Eaton wrote:
> Octave's numel function accepts extra arguments:
>
> octave:1> help numel
> 'numel' is a built-in function from the file libinterp/corefcn/data.cc
>
>   -- numel (A)
>   -- numel (A, IDX1, IDX2, ...)
>       Return the number of elements in the object A.
> [...snip...]
> Does Matlab still accept this usage?  It does not appear to be 
> documented now.

It may not be documented, but I believe that this calling form is still 
implicitly used by the Matlab runtime in conjunction with overloaded 
subsref and/or subsasgn for user-defined classes. (Remember when we were 
discussing subref/sugsasgn semantics in IRC a week or so ago and you 
were like, "WTF?"?) So, it's not just accepted, but required in some 
cases, WRT classdef classes.

> Is the function numArgumentsFromSubsctript somehow related to this 
> (apparently obsolete) way of calling numel?

I believe it is, but I'm not aware of any doco specifying how it works, 
or how it interacts with numel().

Cheers,
Andrew