Hack - how to check that an instance uses a Trait?

Question

How can I check if a an instance of a class uses a Trait? I can't use instanceof because the Trait is uninstantiable.

Answer 1

Hack is a super set of PHP (and also a sub set, given some legacy stuff was removed), so most of the native functions can be used.

With that being said, you have the class_uses() function, that does what you want.

Here's a simplified use case:

if (in_array(\Foo\Bar::class, class_uses($object))) {
    // Do something if $object is using \Foo\Bar trait
}