I've updated the code to use ::class, I've also fixed the same issue in Translation component

Thank you @Nyholm.

Thank you for merging.

If you installed a command line tool like psalm
[...]
I've updated the code to use ::class

Ironically, this broke Psalm tests: https://github.com/vimeo/psalm/runs/2037304361#step:7:42

I would suggest to replace

if (!\function_exists(u::class)) {

with

if (!\function_exists(__NAMESPACE__ . '\\u')) {

The current implementation is valid PHP code. I’m not sure what the benefits are to implement to your suggestion.

I don’t want to be disrespectful, but this is a problem psalm should fix, isn’t it?

I’m not sure what the benefits are to implement to your suggestion.

Clearer code, mostly. I had this little 'huh?' moment looking at it, thinking 'What are those weirdly named classes? And why are they used in function_exists()? Oh, those are not classes...'

this is a problem psalm should fix, isn’t it?

Perhaps. Hardly a high-priority issue though, as in practice it will only happen when people run Psalm with badly written custom autoloader.