Why is it that no one writes with portability in mind in druntime?

Sun Nov 24 15:30:34 PST 2013

On Sunday, 24 November 2013 at 17:50:20 UTC, Shammah Chancellor 
wrote:
> Having 80-bit reals on platforms that support them are helpful 
> for numerical simulations.  There use to be an article about 
> this decision. However, phobos should never use real for this 
> reason.

What, so mathematical functions shouldn't use the 
highest-precision floating point?