[swift-evolution] [late pitch] UnsafeBytes proposal

[Andrew Trick]

> On Aug 12, 2016, at 7:32 PM, Brent Royal-Gordon <brent at architechies.com> wrote:
> 
>> On Aug 12, 2016, at 6:12 PM, Andrew Trick via swift-evolution <swift-evolution at swift.org> wrote:
>> 
>> This proposal adds basic usability for working with raw memory without breaking source. The need to provide higher level API for working with raw memory buffers has always been evident, but making improvements in this area depended on first introducing `UnsafeRawPointer`. It was not clear until the final week of source-breaking changes whether SE-0107 would make it into Swift 3. Now that it has, we should use the little remaining time to improve the migration experience and encourage correct use of the memory model by introducing a low-risk additive API.
>> 
>> Proposal:
>> 
>> https://github.com/atrick/swift-evolution/blob/unsafebytes/proposals/NNNN-UnsafeBytes.md
>> 
>> <NNNN-UnsafeBytes.md>
> 
> I've only read a little but so far, but: Is the difference between this and UnsafeBufferPointer that it's built around a raw pointer rather than a bound pointer? If so, would UnsafeRawBufferPointer be a better name?

Yes that’s exactly right. Semantically, reads or writes on `UnsafeBytes` are untyped memory accesses. So you can get bytes into or out of it without binding memory.

But as you’ll see from the interfaces and examples I’ve shown, `UnsafeMutableRawBufferPointer` would be a terrible name. There’s no reason from the user’s point of view to link this type to `UnsafeBufferPointer` and that names conveys no additionally useful information.  It’s often viewed as just a collection of Bytes and potentially an important type for a number of public interfaces.

-Andy