use strict;
use warnings;
use Benchmark 'cmpthese';
undef $/;
my $str = <DATA>;

my @regexen = ( qr/foo/, qr/bar/ );
cmpthese(-2, {
        alternation => sub { my @m = $str =~ /(foo|bar)/g },
        map         => sub { my @m = map $str =~ /$_/g, @regexen },
        loop        => sub { my @m; push @m, $str =~ /$_/g for @regexen },
});

cmpthese(-2, {
        alt_s  => sub { my $s2 = $str; $s2 =~ s/(foo|bar)//g },
        loop_s => sub { my $s2 = $str; $s2 =~ s/$_//g for @regexen}
});

__DATA__
This string contains foo and bar for fools and bards
and I pity the foo who bars the way