php-65576.php

<?php

trait T
{
  public function __construct()
  {
    echo "Trait contructor";
  }
}

class A
{
  public function __construct()
  {
    echo 'Parent constructor';
  }
}

class B extends A
{
  use T;
}

new B();
// Output:
// Trait constructor

trait T2
{
  public function __construct()
  {
    parent::__construct();
    echo "Trait contructor";
  }
}

class A2
{
  public function __construct()
  {
    echo 'Parent constructor';
  }
}

class B2 extends A2
{
  use T;
}

new B2();
// Output:
// Parent constructor
// Trait constructor