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

[Joseph Rushton Wakeling]

On 24/12/13 11:38, Francesco Cattoglio wrote:
>> Ah, nice. There's an unstated assumption here - adding inc n times is the same
>> as adding n * inc.
> Right, completely missed that. I guess checking a few test cases at compile time
> is the best one can do. Checking for every n could take some infinite amount of
> time :P

Example case:

     iota(x, y, (x - y) / N)

... where x and y are floating point and N is anything other than a power of 2. 
  You will probably wind up with cases where you get an unexpected extra point 
on the end that is (x - y - tinyEpsilon).

DMD may be more prone to this than GDC/LDC.  I once ran into a very amusing 
error with DMD (not using iota) when I tried to traverse the closed interval 
[0.0, 1.0] in increments of 0.1.