on Mon Apr 25 2016, Stephen Canon <[email protected]> wrote:
> On Apr 24, 2016, at 6:08 PM, Xiaodi Wu via swift-evolution > <[email protected]> wrote: > > Something else to consider if you insist that all floating point values > must > be "orderable" would be how two NaNs are ordered if they have different > payloads. As far as I'm aware, that goes beyond what IEEE 754 has to say > about total ordering of floating point values. > > The IEEE 754 totalOrder predicate is an honest-to-god total order on all > canonical members of a format (this includes ordering all NaNs by sign, > signalingness, and payload). And that, almost by itself, is enough justification for us to use this ordering for the result of <=> on floats. The fact that this ordering is consistent with the results of < (for values that are ordered with respect to <) is a bonus. -- Dave _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
