[swift-evolution] [swift-evolution-announce] [Review] SE-0067: Enhanced Floating Point Protocols

[Stephen Canon]

> On Apr 22, 2016, at 11:26 AM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
> 
> On Fri, Apr 22, 2016 at 9:56 AM, Stephen Canon <scanon at apple.com> wrote:
>> 
>> On Apr 22, 2016, at 10:54 AM, Xiaodi Wu <xiaodi.wu at gmail.com> wrote:
>> 
>> Naive question: is it necessary to make a trade-off here? Why not an
>> associated type Exponent that's Int for Float, Double, and Float80,
>> allowing for something else for bignums?
>> 
>> 
>> It’s an added (fairly minor) complexity to the API surface that confers
>> approximately zero benefit.
> 
> Alternatively, could `exponent` could be of type Self, just as `significand` is?

IEEE 754 allows this (“If logBFormat is a floating-point format, then the following operations are homogeneous), but IMO this makes the property more awkward to use in practice.

– Steve