++ Yes, that works and is less complicated still. :-)

It wouldn't have occurred to me not to use a capture group. I checked the online docs and found in perlretut - Using regular expressions in Perl - Global matching (after following links from perlre):

In list context, //g returns a list of matched groupings, or if there are no groupings, a list of matches to the whole regexp. [my emphasis]

That seemed new to me (those links are for 5.16.2), so I checked back to the earliest online perldoc version (5.8.8) and, while in a different manpage (http://perldoc.perl.org/5.8.8/perlop.html#Regexp-Quote-Like-Operators) with different wording, that behaviour was current back then:

In list context, it returns a list of the substrings matched by any capturing parentheses in the regular expression. If there are no parentheses, it returns a list of all the matched strings, as if there were parentheses around the whole pattern. [my emphasis, again]

I've learned something new. Thankyou.