Replacement for snprintf

[Stefan Koch]

On Wednesday, 30 October 2019 at 13:44:52 UTC, berni44 wrote:
> In PR 7222 [1] Robert Schadek suggested replacing the call to 
> snprinf in std.format with an own method written in D. During 
> the last days I took a deeper look into this and meanwhile I've 
> got a function that works for floats

If you could post that so I can have a look over the WIP that'd 
be nice.

Grisu2 also uses lookup tables, though for 52bit mantissa floats 
it's completely fine.