(octave.info)Variable-length Return Lists

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11.6 Variable-length Return Lists
=================================

It is possible to return a variable number of output arguments from a
function using a syntax that’s similar to the one used with the special
‘varargin’ parameter name.  To let a function return a variable number
of output arguments the special output parameter name ‘varargout’ is
used.  As with ‘varargin’, ‘varargout’ is a cell array that will contain
the requested output arguments.

   As an example the following function sets the first output argument
to 1, the second to 2, and so on.

     function varargout = one_to_n ()
       for i = 1:nargout
         varargout{i} = i;
       endfor
     endfunction

When called this function returns values like this

     [a, b, c] = one_to_n ()
          ⇒ a =  1
          ⇒ b =  2
          ⇒ c =  3

   If ‘varargin’ (‘varargout’) does not appear as the last element of
the input (output) parameter list, then it is not special, and is
handled the same as any other parameter name.

 -- : [R1, R2, ..., RN] = deal (A)
 -- : [R1, R2, ..., RN] = deal (A1, A2, ..., AN)

     Copy the input parameters into the corresponding output parameters.

     If only a single input parameter is supplied, its value is copied
     to each of the outputs.

     For example,

          [a, b, c] = deal (x, y, z);

     is equivalent to

          a = x;
          b = y;
          c = z;

     and

          [a, b, c] = deal (x);

     is equivalent to

          a = b = c = x;

     Programming Note: ‘deal’ is often used with comma separated lists
     derived from cell arrays or structures.  This is unnecessary as the
     interpreter can perform the same action without the overhead of a
     function call.  For example:

          c = {[1 2], "Three", 4};
          [x, y, z] = c{:}
          ⇒
             x =

                1   2

             y = Three
             z =  4

     See also: Note: cell2struct, *note struct2cell:
     XREFstruct2cell, Note: repmat.