#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

cmpthese -1, {
    one_eval => q[
        my $t = 1;
        eval qq[ sub count { \$_[0] =~ tr[$t][$t] } ];
        my $c = 0;
        $c += count( $_ ) for 1 .. 1e6;
        print $c;
    ],
    many_evals => q[
        my $t = 1;
        my $c = 0;
        $c += eval qq[ \$_ =~ tr[$t][$t] ] for 1 .. 1e6;
        print $c;
    ],
};

__END__
C:\test>junk30
600001
600001
            (warning: too few iterations for a reliable count)

600001
Subroutine count redefined at (eval 2000016) line 1.
600001
Subroutine count redefined at (eval 2000017) line 1.
600001
Subroutine count redefined at (eval 2000020) line 1.
600001
            (warning: too few iterations for a reliable count)

           s/iter many_evals   one_eval
many_evals   27.3         --       -98%
one_eval    0.416      6451%         --