view examples/code/structdemo.cc @ 20616:fd0efcdb3718

use new string_value method to handle value extraction errors * dirfns.cc, file-io.cc, gammainc.cc, help.cc, load-path.cc, octave-link.cc, qz.cc, regexp.cc, strfns.cc, syscalls.cc, time.cc, variables.cc: Use new string_value method.
author John W. Eaton <jwe@octave.org>
date Thu, 08 Oct 2015 19:00:51 -0400
parents 2f8500ca91d3
children
line wrap: on
line source

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

DEFUN_DLD (structdemo, args, , "Struct Demo")
{
  if (args.length () != 2)
    print_usage ();

  if (! args(0).is_map ())
    error ("structdemo: ARG1 must be a struct");

  octave_scalar_map arg0 = args(0).scalar_map_value ();
  //octave_map arg0 = args(0).map_value ();

  if (! args(1).is_string ())
    error ("structdemo: ARG2 must be a character string");

  std::string arg1 = args(1).string_value ();

  octave_value tmp = arg0.contents (arg1);
  //octave_value tmp = arg0.contents (arg1)(0);

  if (! tmp.is_defined ())
    error ("structdemo: struct does not have a field named '%s'\n",
           arg1.c_str ());

  octave_scalar_map st;

  st.assign ("selected", tmp);

  return octave_value (st);
}