my %order_line = read_from_csv();
my @fields = qw(firstname lastname);
my %identity;
@identity{@fields} = @order_line{@fields};
my $customer = Customer->find_or_create(\%identity);

##</code><code>##

my %order_line = read_from_csv();
my @fields = qw(firstname lastname);
my $customer =
  Customer->find_or_create({ map {$_ => $order_line{$_}} @fields });

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;
use Benchmark 'cmpthese';

my $count = shift || -1;
my %source_hash = (
    firstname => 'Perl',
    lastname => 'Monks',
    address_line1 => 'http://www.perlmonks.org',
    address_line2 => 'http://www.perlmonks.com',
    city => 'cyber',
    zip => '209.197.123.153',
    state => 'stable',
    country => 'Internet',
    order_number => 'N/A',
    title => 'not applicable',
);
my @partial = qw(firstname lastname);

cmpthese $count, {
    with_slice => sub {
        my %target_hash;
        @target_hash{@partial} = @source_hash{@partial};
    },
    with_map => sub {
        my %target_hash =
            map {$_ => $source_hash{$_}}
                @partial;
    },
};

# Result:
#                Rate   with_map with_slice
# with_map   110277/s         --       -28%
# with_slice 153325/s        39%         --