Added Nette\Caching\Cache dynamic return type extensions

[adaamz]

[ondrejmirtes]

Hi, I worry that some cases will not work well, for example:

	/**
	 * @template TFallback
	 * @param mixed $key
	 * @param (callable(mixed): TFallback)|null $fallback
	 * @return TFallback
	 */
 	public function load($key, callable $fallback = null)

If the fallback is not passed, we have an unresolved TFallback.

And in some other cases I'm not sure that callable(mixed) is right, there might be none or more arguments passed.

[adaamz]

Can we somehow tell that if no fallback is passed it should return null?

In source is this https://github.com/nette/caching/blob/be02f7e/src/Caching/Cache.php#L104, so the parameter should be only one?

[ondrejmirtes]

1. TFallback - nope, at that point you can't use generics, but need a dynamic return type extension instead.
2. There are three callable(mixed) in the stubs, is it true for all of those? What's the diferrence between fn(&$dependencies) and fn(...[&$dependencies])?

[adaamz]

1. OK, introduced dynamic return type extensions for all previously stubbed methods
2. i have no clue, im really lost in references in php :)