doc: Update documentation for functions in octave-value dir. * ov-bool-mat.cc (Flogical): Document that input must be numeric. Document incompatibility with Matlab regarding complex inputs. * ov-cell.cc (Fcell): Add seealso references. * ov-cell.cc (Fcellstr): Document that trailing spaces are trimmed. Add seealso references. * ov-cell.cc (Fstruct2cell): Use lowercase names in @var references. * ov-class.cc (Fismethod): Add seealso reference to isprop. * ov-class.cc (Fsuperiorto): Add seealso reference to inferiorto. * ov-class.cc (Finferiorto): Add seealso reference to superiorto. * ov-fcn-handle.cc (Ffunctions): Add table to documentation describing return values. * ov-fcn-handle.cc (Ffunc2str): Add seealso links to str2func, functions. * ov-fcn-handle.cc (Fstr2func): Add seealso links to func2str, inline. * ov-fcn-handle.cc (Fis_function_handle): Add seealso links to functions. * ov-fcn-inline.cc (Finline): Add note that the use of inline is discouraged. Add seealso link to str2func. * ov-int16.cc (Fint16): Add seealso links to docstring. * ov-int32.cc (Fint32): Add seealso links to docstring. * ov-int64.cc (Fint64): Add seealso links to docstring. * ov-int8.cc (Fint8): Add seealso links to docstring. * ov-oncleanup.cc (FonCleanup): clarify docstring by using "function" rather than "action" for what gets called when onCleanup object is destroyed. * ov-struct.cc (Fstruct): Add additional calling forms. Add seealso links. * ov-struct.cc (Fisfield): Add additional calling forms. Add seealso link. * ov-struct.cc (Fnfields): Add seealso link. * ov-struct.cc (Fcell2struct): Add additional calling forms. Add seealso link. * ov-struct.cc (Frmfield): Emphasize that a copy of the struct is returned. Add seealso link. * ov-struct.cc (Fstruct_levels_to_print): Add seealso link to print_struct_array_contents. * ov-struct.cc (Fprint_struct_array_contents): Add seealso link to struct_levels_to_print. * ov-typeinfo.cc (Ftypeinfo): Add seealso links to class, isa. * ov-uint16.cc (Fuint16): Add seealso links to docstring. * ov-uint32.cc (Fuint32): Add seealso links to docstring. * ov-uint64.cc (Fuint64): Add seealso links to docstring. * ov-uint8.cc (Fuint8): Add seealso links to docstring. * ov-usr-fcn.cc (Fnargin): Add example based on 'union' function. * ov-usr-fcn.cc (Fnargout): Add example based on 'imread' function. * ov-usr-fcn.cc (Foptimize_subsasgn_calls): Improve docstring. * ov.cc (Fsubsref): Rephrase one sentence. * fieldnames.m: Add more functions to seealso links. * getfield.m: Re-order seealso links. * setfield.m: Re-order seealso links. * isprop.m Add ismethod, isobject to seealso links.

## Copyright (C) 2010-2013 Ben Abbott
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{res} =} isprop (@var{h}, "@var{prop}")
## Return true if @var{prop} is a property of the object with handle @var{h}.
##
## @var{h} may also be an array of handles in which case @var{res} will be a
## logical array indicating whether each handle has the property @var{prop}.
## @seealso{get, set, ismethod, isobject}
## @end deftypefn

## Author: Ben Abbott  <bpabbott@mac.com>

function res = isprop (h, prop)

  if (nargin != 2)
    print_usage ();
  endif

  if (! all (ishandle (h)))
    error ("isprop: H must be a graphics handle or vector of handles");
  elseif (! ischar (prop))
    error ("isprop: PROP name must be a string");
  endif

  res = false (size (h));
  for i = 1:numel (res)
    try
      v = get (h(i), prop);
      res(i) = true;
    end_try_catch
  endfor
endfunction


%!assert (isprop (0, "foobar"), false)
%!assert (isprop (0, "screenpixelsperinch"), true)
%!assert (isprop (zeros (2, 3), "visible"), true (2, 3))

%!error isprop ()
%!error isprop (1)
%!error isprop (1,2,3)
%!error <H must be a graphics handle> isprop ({1}, "visible")
%!error <PROP name must be a string> isprop (0, {"visible"})