Phobos math expert wanted: Please help porting std.conv.parse to 64bit reals

[Jerry]

Johannes Pfau <nospam at example.com> writes:

> std.conv.parse!(real) and therefore also parse!double, parse!float were
> written assuming real is always a 80 bit type. But on most non x86
> systems the largest floating point type is actually double and
> therefore real is basically an alias for double. std.conv makes some
> convenient assumptions for 80bit reals (like mantissa size is ==
> long.sizeof). I guess this is a simple fix for math/floating point
> experts but I'd need quite some time to fix it. So it'd be great if
> someone could help and port std.conv.parse to systems with 64 bit reals
> (real.mant_dig == 113) :-)
>
> https://github.com/D-Programming-Language/phobos/blob/master/std/conv.d#L2367

First step, please enter a bug so that the issue doesn't get lost.

I may be able to look at it a little tonight.  I'm not an expert, but I
have some experience with floating point conversion.

Jerry