That is a rather odd statement, but completely valid since at least Perl 5.6 "mid-90's".

my @anyname = some match regex global expression;
my $c = @anyname;  #scalar value of number of elements in @anyname
# The Goatse means the same thing but you don't have to have to
# Updated spelling of Goatse, one "e", not two - Ooops thanks YourMoth
+er
# have the array @anyname
[download]

In general my code usually processes each match from a "match global".
I think I've used this construct before, but this is definitely not common.
More common is whether or not a match exists - not how many.