Actually, the empty regexp, // is special. See perlre, resp. perlop. 
say "foo" =~ /oo/ ? "MATCH" : "NO MATCH";
say "bar" =~ // ? "MATCH" : "NO MATCH";
MATCH
NO MATCH

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An empty pattern repeats the last successful match.

In reply to Re^2: Perl bug or feature? by JavaFan
in thread Perl bug or feature? by yegg

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