Combine two or more types of classes (or array) to be required by the class property, local variable or a return type of the function.
New support for pure intersection types are specified using the syntax T1&T2&... and can be used in all positions where types are currently accepted:
class A {
private Traversable&Countable $countableIterator;
public function setIterator(Traversable&Countable $countableIterator): void {
$this->countableIterator = $countableIterator;
}
public function getIterator(): Traversable&Countable {
return $this->countableIterator;
}
}This means it would not be possible to mix intersection and union types together such as A&B|C, this is left as a future scope.
More examples of union types:
function foo(): A&A {} // Disallowed
use A as B;
function foo(): A&B {} // Disallowed ("use" is part of name resolution)
class_alias('X', 'Y');
function foo(): X&Y {} // Allowed (redundancy is only known at runtime)class A {}
class B extends A {}
class Test {
public A&B $prop;
}
class Test2 extends Test {
public B $prop;
}
