SE-0259: Approximate Equality for Floating Point

[gwendal.roue (Gwendal Roué)]

@tomkeith

It would be nice to have something like

func isAlmostEqual( to other: Self, absoluteTolerance: Self ) -> Bool

rather than having to subtract the value you are checking against so you can use isAlmostZero() .

I concur. Especially if (a-b).isAlmostZero(absoluteTolerance: ...) is a naive and wrong way to do it (it's easy to grow a small amount of paranoia when dealing with floats).