Should this work?

[monarch_dodra]

On Friday, 10 January 2014 at 14:31:31 UTC, John Colvin wrote:
> or if you want something short and simple, define a free 
> function:
> auto popFrontRet(R)(ref R range)
>     if(isInputRange!R)
> {
>     range.popFront();
>     assert(!range.empty);
>     return range.front;
> }

*Unless* I'm mistaken, he was asking for something that returns 
the *popped* element?

Re-reading the question, it does kind of sound a bit ambiguous 
now.