> Le 9 juil. 2025 à 02:47, Juliette Reinders Folmer <php-internals_nospam@adviesenzo.nl> a écrit :
>
> L.S.,
>
> I just noticed something which seems odd to me: PHP 8.1 deprecated declaring a function to return by reference when the return type is void:
>
> `function &foo() : void {}` results in:
> "Deprecated: foo(): Returning by reference from a void function is deprecated"
>
> However, declaring a function to return by reference when the return type is "never" does not yield either an error or a deprecation notice: https://3v4l.org/DWs7t
>
> I might well be missing something, but this feels a bit strange and inconsistent to me.
>
> Should this be fixed by also deprecating return by reference for "never" functions ?
>
> Smile,
> Juliette
>
>
Hi Juliette,
The two cases are subtly different, and this can be illustrated by the following example:
Suppose you have an interface mandating to implement a method that returns something by reference.
When you implement that interface, you must provide a method that returns by reference, but you are free to actually never return from it—restricting the return type to `never`.
On the other hand, you cannot implement it with a method that doesn’t provide a value when returning—changing the return type to `void`.
In other words, although the combination of “by reference” and “never” is not useful in isolation, it makes nevertheless sense when you think of “never” as a special case of “a value that satisfies a set of constraints”.
—Claude
