nur-sery/wip/php/access/ValueAccess.php

<?php
namespace nur\sery\wip\php\access;

/**
 * Class ValueAccess: accès à une valeur scalaire
 */
class ValueAccess extends AbstractAccess {
  function __construct(&$dest) {
    $this->dest =& $dest;
  }

  /** @var mixed */
  protected $dest;

  function exists(): bool {
    return $this->dest !== null;
  }

  function available(): bool {
    return $this->exists();
  }

  function get($default=null) {
    if ($this->dest === null) return $default;
    else return $this->dest;
  }

  function set($value): void {
    $this->dest = $value;
  }

  function del(): void {
    $this->dest = null;
  }
}