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

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

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

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