php-trait-issue

class.php

<?php

trait Bar {
	public function jsonSerialize() {
		return ["switch" => static::$SWITCH];
	}
}

class Foo implements JsonSerializable {
	public static $SWITCH = false;
	use Bar;
}

$f = new Foo();
Foo::$SWITCH = true;
echo json_encode($f);

// prints {"switch":true}

trait.php

<?php

trait Bar {
	public static $SWITCH = false;
	public function jsonSerialize() {
		return ["switch" => self::$SWITCH];
	}
}

class Foo implements JsonSerializable {
	use Bar;
}

$f = new Foo();
Bar::$SWITCH = true;
echo json_encode($f);

// prints {"switch":false}