It might not seem any different than davorg's solution, but using qr instead of quotes is better. It makes the syntax less problematic if the sub-expression has any special characters in it!

my $space= qr/[\s\xA0]/;
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Hmm, your code sample doesn't parse (you said s// not s///) and it's finding leading OR trailing space. Assuming you just forgot a slash, it will strip leading space if it exists and leave trailing, or strip trailing if there was no leading.