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@ 2015-03-17T21:48:41Z

$value = null; $executed = false; return function () use ($producer, & $value, & $executed) {
			if (!$executed) {
				$value = $producer();
				$executed = true;
			}
			
			return $value;
		};
		
		
		
		
<?php
class Connection {}

class Context {
  public function get_instance(){
     static $i;
     $i ?: $i = new Connection();
     return $i;
  }
}

class A extends Context {}
class B extends A {}

class Context2 {
  public function __constructor() { 
		$this->conn = new Connection(); // Should be lazily created but imagine we have once().
  }
  public function get_instance(){
     return $this->conn;
  }
}

class A2 extends Context2 {}
class B2 extends A2 {}

$a = new A();
$b = new B();
$a2 = new A2();
$b2 = new B2();

var_dump($a->get_instance());
var_dump($b->get_instance());
var_dump($a2->get_instance());
var_dump($b2->get_instance());

Output for git.master, git.master_jit, rfc.property-hooks: $value = null; $executed = false; return function () use ($producer, & $value, & $executed) { if (!$executed) { $value = $producer(); $executed = true; } return $value; }; object(Connection)#5 (0) { } object(Connection)#5 (0) { } Warning: Undefined property: A2::$conn in /in/OYbWc on line 32 NULL Warning: Undefined property: B2::$conn in /in/OYbWc on line 32 NULL

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2020-03-21 RFC: Is_Literal - declined
2020-12-04 Enumerations - included in PHP 8.1
2018-06-15 Typed Properties v2 - implemented in PHP 7.4
2016-08-12 Object typehint - included in PHP 7.2
2016-08-14 Arrow functions - withdrawn
2016-05-29 array_change_keys() - withdrawn
2016-04-19 Lexical scope support for anonymous classes - suspended
2016-04-17 Functional Interfaces - declined
2016-03-16 Typed Properties - superseded in favor of Typed Properties 2.0
2015-08-27 Callable Prototypes - declined
2015-05-01 Short Closures - declined / withdrawn in favor of Arrow Functions
2015-02-18 Scalar type hints v5 - included in PHP 7
2015-02-14 Union Types - declined
2013-09-22 Anonymous classes - included in PHP 7

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