pop & popFront combined

["Nordlöw" via Digitalmars-d-learn]

On Saturday, 1 November 2014 at 11:43:28 UTC, Nordlöw wrote:
> if (!x.empty)
>     if (auto front = x.stealFront)
>     {
>         front.doStuff;
>     }
>
> This is more functional/atomic, that is it reduces the risk of 
> accidentally forgetting to call popFront at the end.

Forgot my explicit question:

So why isn't something like x.stealFront already in Phobos?