96 DEFUN (isnull, args, ,
98 @deftypefn {Built-in Function} {} isnull (@var{x})\n\
99 Return true if @var{x} is a special null matrix, string, or single quoted\n\
102 Indexed assignment with such a value on the right-hand side should delete\n\
103 array elements. This function should be used when overloading indexed\n\
104 assignment for user-defined classes instead of @code{isempty}, to\n\
105 distinguish the cases:\n\
108 @item @code{A(I) = []}\n\
109 This should delete elements if @code{I} is nonempty.\n\
111 @item @code{X = []; A(I) = X}\n\
112 This should give an error if @code{I} is nonempty.\n\
114 @seealso{isempty, isindex}\n\
119 int nargin = args.
length ();
121 if (nargin == 1 && args(0).is_defined ())
static octave_base_value * default_null_sq_str_numeric_conversion_function(const octave_base_value &a)
static const octave_value instance
OCTINTERP_API void print_usage(void)
#define DEFUN(name, args_name, nargout_name, doc)
static int static_type_id(void)
#define DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA(t, n, c)
static octave_base_value * default_null_str_numeric_conversion_function(const octave_base_value &a)
static const octave_value instance
type_conv_info numeric_conversion_function(void) const
bool is_null_value(void) const
static const octave_value instance
static int static_type_id(void)
virtual octave_base_value * empty_clone(void) const
octave_idx_type length(void) const
type_conv_info numeric_conversion_function(void) const
static int static_type_id(void)
type_conv_info numeric_conversion_function(void) const
static octave_base_value * default_null_matrix_numeric_conversion_function(const octave_base_value &a)