Printing floating points

[deadalnix]

On Thursday, 21 January 2021 at 14:13:32 UTC, Stefan Koch wrote:
> I think Ilya has implemented this in mir already.
> ryu is less of a breakthrough imo.
> It's a modification of grisu2 (hence the name ryu (dragon in 
> Japanese))

ryu pushes thing forward significantly, and proved it was correct 
to do so. I can't stress enough the importance of that last part, 
because there are no way you can check all possible double values 
by yourself and see if the output is correct.