Rational numbers in D

[Paul D. Anderson]

It seems like we ought to have rational numbers in Phobos along 
with other number types. Something like this:

std.number.rational;
std.number.decimal;
std.number.integer; (fixed-size signed and unsigned integers, 
"safe" integers that throw on overflow or rollover, like Andrei's 
CheckedInt module, etc.
std.number.complex; (I know, I know)
std.number.quaternion;
std.number.fixedpoint;
std.number.interval (Interval arithmetic on floating-point 
numbers)

We also need compatible scalar, vector, matrix, multiarray 
modules, etc.

Many of these exist, but aren't incorporated in Phobos. I think 
we need to be more aggressive in recruiting functionality for 
Phobos. There are a lot of talented coders out there.

Paul