n[:m]:end -- gap in the documentation?

[Olaf Pohlmann]

Hi,

say you want to change every other element of a vector. You can do it like this:
b = [2, 5, 7, 0.2];
b([2:2:max(size(b))]) += 4
b =

   2.0000   9.0000   7.0000   4.2000

Someone, who is familiar with Matlab, pointed out to me that the
second line can be written as
b([2:2:end]) +=4;

This feature doesn't seem to be mentionend anywhere in the docs, and
even the tutorial sections about ranges
http://www.gnu.org/software/octave/doc/interpreter/Ranges.html
and index expressions
http://www.gnu.org/software/octave/doc/interpreter/Index-Expressions.html
keep quiet about it, but it does work, and it seems to be implemented
since version 2.x already.

Is this just a gap in the documentation or are there circumstances
where it doesn't work reliably (yet)?


op