confirming comment #2 behavior is still fully present in octave 6.4.0

Confirmed present in the development version. The @myclass directory does not have to be added to the path, as long as the directory containing it is in the path.

In Octave's pwd, in another terminal while Octave is running, create a class constructor:

$ mkdir @myclass
$ cat > @myclass/myclass.m
function x = myclass ()
  x = class (struct (), "myclass");
endfunction

Now in the running Octave, construct an object of type "myclass"

octave:1> x = myclass ()
x = <class myclass>

Now create the method newfunc in the @myclass directory, while the same Octave is still running:

$ cat > @myclass/newfunc.m
function y = newfunc (x)
  y = x;
endfunction

And back inside Octave:

octave:2> newfunc (x)
error: 'newfunc' undefined near line 1 column 1
octave:3> rehash
octave:4> newfunc (x)
error: 'newfunc' undefined near line 1 column 1

Now resetting the path makes it work:

octave:5> path (path ());
octave:6> newfunc (x)
ans = <class myclass>

addpath("/directory/containing/folder@myclass")

create a new file @myclass/newfunc.m with valid newfunc function, then invoke it on an object of type myclass

newfunc(c)

error: `newfunc' undefined ...


However if addpath is called AFTER the file is created, in other words if the file exists prior to calling addpath, invocation of newfunc(c) works just fine.