std.range.iota enhancement: supporting more types (AKA issue 10762)

[Jakob Ovrum]

On Tuesday, 24 December 2013 at 11:25:04 UTC, Francesco Cattoglio 
wrote:
> There's a catch: if we want bidirectional, we need the last 
> element of the range.

`end` is a parameter to all overloads of `iota`. Note that it is 
exclusive, so the first `back` is `--end`, not `end` as passed in 
by the caller.

Are you sure you understand bidirectional ranges correctly? Any 
range that has the `back` property and `popBack` method are 
bidirectional.