The rfind challenge

[Andrei Alexandrescu]

On 1/15/13 1:31 AM, H. S. Teoh wrote:
> Hmm. What about introducing a new primitive takeUntil, that returns the
> initial segment of the range until a given predicate becomes true? Then
> you could implement rfind thus:
>
> 	auto rfind(alias pred, R)(R range)
> 		if (isBidirectionalRange!R)
> 	{
> 		return range.retro()
> 			.takeUntil!pred()
> 			.retro();
> 	}

That works, but returns a different type. Ideally rfind would return the 
same type as the initial range, R.

Andrei