gistfile1.pl

#!/usr/bin/env perl

use strict;
use warnings;
use Encode qw/encode decode find_encoding/;
use Benchmark qw/timethese cmpthese/;

my $bytes = '小飼弾はアルファブロガー';

my $enc = find_encoding 'utf8';

cmpthese timethese 0, {
	normal => sub {
		my $str = decode utf8 => $bytes;
		my $_bytes = encode utf8 => $str;
	},
	find_encoding => sub {
		my $str = $enc->decode($bytes);
		my $_bytes = $enc->encode($str);
	},
};