ch-ch-update: series, closed-form series, and strides

[Andrei Alexandrescu]

Steven Schveighoffer wrote:
> One thing I was confused about, you are defining in the function how to 
> calculate a[n+1]?  I find it more intuitive to define what a[n] is.  For 
> example,
> 
> auto fib = series!("a[n - 2] + a[n - 1]")(1, 1); // reads a[n] = a[n-2] + 
> a[n-1]
> 
> It's even less confusing in the factorial example (IMO):
> 
> auto fact = series!("a[n - 1] * n")(1);
> 
> Of course, I don't know how the template-fu works, so I'm not sure if it's 
> possible ;)

It's entirely possible, and I think it's a good idea. I'll look into 
changing the code. Thanks!

Andrei