#!perl -l

my $code = sub { wantarray ? 1 : 0 };

sub wrapper {
    my @r = wantarray ? &$code : scalar &$code;

    # ... later

    # Convert the array to a list to alter the
    # behaviour when assigning to a scalar.
    return @r[0..$#r];
}

print wrapper;         # 1
print scalar wrapper;  # 0