<?php
$someBuffer = new Buffer();
$someBuffer('a string');
$someBuffer(array('an array'));
 
$otherBuffer = new Buffer();
$otherBuffer('another string');
 
print json_encode($otherBuffer->release())."\n";
 
echo "\nПочему \$otherBuffer скопировало \$someBuffer ?!! Это же разные инстансы.";
 
class Buffer
{
  protected static $stock = array();
 
  public function clear() {
    self::$stock = array();
  }
 
  public function __invoke($resource = array(), $key = false) {
    if ($key) {
      self::$stock[$key] = $resource;
    } else {
      self::$stock[] = $resource;
    }
  }
 
  public function release() {
    return self::$stock;
  }
}

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