Michael G Schwern wrote:
[...]
That said, here's the main differences:
* No qr//. Even if you target 5.5.4 qr// still has lots of bugs.
[...]
Once you go through the initial pain of backporting its not too big a deal
to keep things working as long as you're not doing XS. qr// is the only
thing I really miss.
I like to use constant when I can, but the further you go back in time
the more brain-damaged it becomes. I think in 5.005 it only knows about
scalars. No hashrefs or arrayrefs allowed. I find this is a bit of a
bugger to work around.
There are the following documents
perl5004delta
perl5005delta
perl56delta
perl561delta
etc.
that can give clues as to when what language features were added or
changed. I thought history.perl.org covered this in more detail but
apparently not.
David
