Will passing an array as a value in puppet install my package?

I'm working through the puppet documentation. One of the exercises is to use some conditional logic to write a general install manifest:

Exercise: Use the $operatingsystem fact to write a manifest that installs a build environment on Debian-based (“debian,” “ubuntu”) and Enterprise Linux-based (“centos,” “redhat”) machines. (Both types of system require the gcc package, but Debian-type systems also require build-essential.)

I wrote code that works, but because my machine is a centos machine, I have no way of checking if the branch works:

$build_packages = $::operatingsystem ? {
  /(?i)centos|redhat/ => 'gcc',
  /(?i)debian|ubuntu/ => ['gcc','build-essential'],
  default => undef
}

notify {"build_packages":
  message => "Build packages for ${::operatingsystem} are: ${build_packages}\n",
  before => Package['build']
}

package {'build':
  ensure => installed,
  name => $build_packages
}

My question is, if I was on a debian or ubuntu system, would this work? Specifically, if I set $build_packages to an array, will the package resource do the right thing and install the two packages? Or should I redefine that resource like this?:

package {$build_packages:
    ensure => installed
}