callable.notSupported

Code example

<?php declare(strict_types = 1);

class Foo
{
	public function doFoo(): void
	{
		$callable = $this->doFoo(...);
	}
}

Why is it reported?

First-class callable syntax (foo(...)) was introduced in PHP 8.1. When PHPStan is configured to analyse code for a PHP version earlier than 8.1, using this syntax is not valid and will cause a syntax error at runtime.

This error is also reported when trying to create a callable from the new operator (e.g., new Foo(...)), which is not supported in any PHP version.

How to fix it

Use a Closure::fromCallable() call or a closure wrapper instead of the first-class callable syntax:

 <?php declare(strict_types = 1);

 class Foo
 {
 	public function doFoo(): void
 	{
-		$callable = $this->doFoo(...);
+		$callable = Closure::fromCallable([$this, 'doFoo']);
 	}
 }

Or configure PHPStan to analyse the code for PHP 8.1 or later by setting the phpVersion option in the configuration file.