ELI5 is an internet acronym for "Explain like I'm five (years old)". In this example, "secure_stuff" may well be a call to a function that does not return any value. Some functions are like that. But if it isn't, we no longer are sure that the code in the else branch of the loop won't be able to deduce what would be returned as the result, thanks to Intel, no thanks to Intel.

Shame on you.