Classdef
This page is a stub. We should begin documenting what classdef is implemented and what is not.
Not Supported
- enumeration
See #44582 and help implementing it.
- build-in class as superclass
classdef nonsense < uint32
end
See #44035
Example:
classdef MyClass < handle
end
c = MyClass();
cc = [c, c]; % won't work
For now you can use a cell-array of objects instead:
cc = {c, c}; % ok
Also see #44665
- Immutable property set access.
Example:
classdef MyClass < handle
properties (SetAccess = immutable)
x
end
methods
function obj = MyClass()
x = rand();
end
end
end
Use "private" properties as workaround.
- Function handles to package methods and static class methods.
For example if we have +mypackage/myfunc.m, creating a function handle as fh = @mypackage.myfunc won't work.
As a workaround, we can create an indirection using an anonymous function fh = @(varargin) mypackage.myfunc(varargin{:}).
Similarly for static class methods where fh = @MyClass.myfunc isn't yet supported. Another workaround for package function handles is to use str2func, e.g. fh = str2func ("mypackage.myfunc").
A fuller example is also given below:
classdef method_function_handle_test
% properties
%
%
% end
properties (Hidden, SetAccess = protected)
hfoo = [];% handle to function
end
methods
function self = method_function_handle_test ()
self.hfoo = @foo;
end
function bar (self)
self.hfoo (self);
end
end
methods (Hidden, Access = protected)
function foo (self)
disp ('hello!');
end
end
end
Then running:
>> x = method_function_handle_test
error: @foo: no function and no method found
error: called from
method_function_handle_test at line 17 column 17
stopped in <****>/scratch/mfiles/octave_tests/method_function_handle_test.m at line 17
17: self.hfoo = @foo;
See #45351
- Defining local functions in the same classdef-file is not working.
For example, the following code gives a syntax/parse error:
classdef MyClass
methods
function obj = MyClass()
myfunc()
end
end
end
function myfunc()
disp('myfunc')
end
See #41723.
- debugging in classdef methods (and +package directory functions)
Breakpoints cannot currently be set in classdef methods from the gui, but only from the command line:
dbstop @aclass\amethod
See #45404
- Saving/reading classdef objects to/from (.mat) file
Supported
- methods
- static
- private
- properties
- SetAccess (public/private/protected)
Open Bug Reports
Issues with basic classdef functionality
- 51659 Calling 'methods' on self causes syntax error
- 48682 print_usage fails within classdef block
- 49434 which returns "built-in function" for classdef m-file
- 48041 classdef: `help myclass` messes up `help @myclass/method`
- 43047 help() does not see classdef files
- 42620 exist() does not use "class" argument
- 53874 doc_cache_create doesnt handle classdef documentation
- 52096 meta.class.fromName throws error when class name not found.
- 51377 Parse error for abstract methods
- 44665 error in concatenation of classdef objects
- 44582 classdef: missing support for enumeration
- 48693 classdef subsref method is not called with correct nargout value
Classdef and +package directories
- 54941 interpreter cannot find methods in files of classdefs in packages
- 54273 Can't access properties of class in package in function defined in class
Arrays of classdef objects
- 53906 Cannot make an object array with square brackets
- 47755 Access to object arrays
- 47241 classdef: assigning property of handle object in object array constructs new object
I/O issues
- 55497 No or wrong default file name when saving a classdef file
- 45833 support load/save of classdef objects
Debugger
- 46451 unable to set breakpoints within classdef classes
- 45404 Breakpoints cannot be set in classdef methods or +package function files
Lower-priority issues
- 55488 Invalid use of colon char as classdef function's argument when subsref is overwritten
- 55487 ismethod of custom classdefs always returning false
- 54966 Error when assigning array to an object implementing subsasgn() subscripted using "{}"
- 54783 subsasgn call when the subscripted expression contains the end keyword
- 54028 copy of non-handle class instance is not deep
- 53811 cellfun does not find overloaded function with function name argument
- 52989 classdef: missing error messages on multiply defined properties
- 52614 setting properties of classdef object during construction with inheritance
- 52582 Dependent constant properties in classdef errors: no such file
- 52123 Indirect memory leak in cdef_manager::initialize ()
- 51285 max_recursion_depth error in classdef constructor
- 50395 subclassing a class that is also defined as a variable fails
- 50011 failure to report error on conflicting methods for classdef
- 49379 classdef constructor: .argn. loses first argument, inputname(n) returns inputname(n+1)
- 46652 whos bytes property not right for classdef classes
- 45893 classdef properties are not reloaded when file is updated
- 44934 classdef parser prints extra newline when failing to parse bad classdef file
- 44643 classdef handle object can go into an recursive loop with isequal(obj1,obj2) if both are self-referential
- 44035 classdef is unable to to subclass double
Documentation