[swift-evolution] [Review] SE-0016 - Adding initializers to Int and UInt to convert from UnsafePointer and UnsafeMutablePointer

[Dave Abrahams]

on Thu Mar 24 2016, Guillaume Lessard <swift-evolution at swift.org> wrote:

>> * What is your evaluation of the proposal?
>
> I support this. Currently this requires the use of unsafeBitCast, which works okay but is unwieldy.
> I used unsafeBitCast to implement tagged pointers in a previous
> exploratory project, and I think this proposal would improve
> readability without being an inducement to recklessness.
>
> “bitPattern” is a decent label, but that is also used for the lossy
> int-to-int conversions; 

No, we never use “bitPattern” for those conversions.  We have
“truncatingBitPattern” where conversions are lossy.

> pointer-to-int casting may be different enough to warrant a different
> label. “unsafeAddress” comes to mind, but may clash with the
> similarly-named function.
>
>> * Is the problem being addressed significant enough to warrant a change to Swift?
>
> Yes.
>
>> * Does this proposal fit well with the feel and direction of Swift?
>
> Yes.
>
>> * If you have you used other languages or libraries with a similar
>> feature, how do you feel that this proposal compares to those?
>
> Like uintptr_t, this requires an intentional step in order to do bit operations on pointers.
>
>> * How much effort did you put into your review? A glance, a quick reading, or an in-depth study?
>
> A careful read and some experience trying this in swift.
>
> Cheers,
> Guillaume Lessard
>
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-- 
Dave