I was taught to use a plus to disambiguate: print +( ... ) is that no longer accepted?

That's still fine in Perl 5, but Perl 6 disambiguates it on the basis of the whitespace alone, which is what most newcomers seem to expect. Also, unary + actually means something in Perl 6, and wouldn't work anymore for the purpose of doing nothing. So the Perl 5 usage is deprecated in that sense. But only if you believe in Perl 6... :-)

Actually, what most people expect is for Perl to read their minds, but we've been having some trouble implementing that part, so we may put it off till Perl 7.