How to use "do_colon_op" in an oct-file?

[Lukas Reichlin]

Dear Octave Community

I'm writing an oct-file [1] for the control package where I want to use the 
colon operator:

        octave_value mat_idx = do_colon_op (1, idx);

However, I get the following compiler error:

__lti_input_idx__.cc:50:28: error: use of undeclared identifier 'do_colon_op'
   octave_value mat_idx = do_colon_op (1, idx);
                          ^

How can I fix this error? Thanks in advance for every help!

Best regards,
Lukas


[1]
https://bitbucket.org/paramaniac/control/src/c9a860ebebc4e5894ac501d5962996b3148c55eb/src/__lti_input_idx__.cc?at=oct&fileviewer=file-view-default


#include <octave/oct.h>
//#include <octave/ov.h>
//#include <octave/ov-colon.h>


DEFUN_DLD (__lti_input_idx__, args, ,
      "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} ischar (@var{x})\n\
Return true if @var{x} is a character array.\n\
@seealso{isfloat, isinteger, islogical, isnumeric, iscellstr, isa}\n\
@end deftypefn")
{
 octave_value_list retval;
 octave_idx_type nargin = args.length ();

 if (nargin == 1 && args(0).is_defined () && args(0).is_cell ())
 {
   octave_idx_type len = args(0).cell_value().nelem();
   octave_idx_type idx = len;

   for (octave_idx_type i = 0; i < len; i++)
   {
     if (args(0).cell_value().elem(i).is_string ())
     {
       idx = i;
       break;
     }
   }

   octave_value mat_idx = do_colon_op (1, idx);
   octave_value opt_idx = do_colon_op (idx+1, len);

   retval(0) = mat_idx;
   retval(1) = opt_idx;
 }
 else
 {
   print_usage ();
 }

 return retval;
}






octave:1> makefile_control 
rm -rf *.o core octave-core *.oct *~ *.f slicot sltmp
LFLAGS="-L/sw/lib/octave/3.8.2 -L/sw/lib -L/sw/lib/lapack/3.5.0 -lreflapack 
-L/sw/lib/lapack/3.5.0 -lrefblas -L/sw/lib/gcc4.9/lib -lgfortran" \
   mkoctfile __control_slicot_functions__.cc common.cc slicotlibrary.a
mkoctfile is_real_scalar.cc
mkoctfile is_real_vector.cc
mkoctfile is_real_matrix.cc
mkoctfile is_real_square_matrix.cc
mkoctfile is_matrix.cc
mkoctfile nfields2.cc
mkoctfile __lti_input_idx__.cc
__lti_input_idx__.cc:50:28: error: use of undeclared identifier 'do_colon_op'
   octave_value mat_idx = do_colon_op (1, idx);
                          ^
__lti_input_idx__.cc:51:28: error: use of undeclared identifier 'do_colon_op'
   octave_value opt_idx = do_colon_op (idx+1, len);
                          ^
2 errors generated.
Makefile:69: recipe for target '__lti_input_idx__.oct' failed
make: *** [__lti_input_idx__.oct] Error 1
make: *** Waiting for unfinished jobs....
ld: warning: could not create compact unwind for _sb10yd_: stack subq 
instruction is too different from dwarf stack size
ld: warning: could not create compact unwind for _mb03xp_: stack subq 
instruction is too different from dwarf stack size
octave:2>