> On Feb 1, 2017, at 4:09 PM, Douglas Gregor via swift-evolution 
> <[email protected]> wrote:
> 
>> 
>> On Feb 1, 2017, at 3:13 PM, David Hart <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> Second question inline:
>> 
>> 
>> 
>> Sent from my iPhone
>> On 1 Feb 2017, at 23:09, David Hart <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>>> I did consider it, but didn’t want to put too much on your plate for Swift 
>>> 4. But if you’re mentioning it, I’ll go ahead and add it to the second 
>>> version of the proposal.
>>> 
>>> By the way, what you is your point of view about the discussions we’ve had 
>>> concerning the positioning of the class constraint?
>>> 
>>> David.
>>> 
>>>> On 1 Feb 2017, at 22:58, Douglas Gregor <[email protected] 
>>>> <mailto:[email protected]>> wrote:
>>>> 
>>>> 
>>>>> On Jan 29, 2017, at 8:39 AM, David Hart <[email protected] 
>>>>> <mailto:[email protected]>> wrote:
>>>>> 
>>>>> Hello,
>>>>> 
>>>>> As promised, I wrote the first draft of a proposal to add class 
>>>>> requirements to the existential syntax. Please let me know what you think.
>>>>> 
>>>>> https://github.com/hartbit/swift-evolution/blob/subclass-existentials/proposals/XXXX-subclass-existentials.md
>>>>>  
>>>>> <https://github.com/hartbit/swift-evolution/blob/subclass-existentials/proposals/XXXX-subclass-existentials.md>
>>>> This looks good! I’m looking forward to the second draft, but I have one 
>>>> question.
>>>> 
>>>> Did you consider the generalized “class” constraint? IIRC, this was in 
>>>> Austin’s larger proposal, and it allowed for (e.g.)
>>>> 
>>>>    typealias CustomStringConvertibleClass = class & 
>>>> CustomStringConvertible    // class that conforms to 
>>>> CustomStringConvertible
>>>> 
>>>> and potentially a wonderful cleanup where AnyObject ceases to be a weird 
>>>> special protocol and instead becomes
>>>> 
>>>>    typealias AnyObject = Any & class
>>>> 
>> 
>> Austin's proposal defines it as:
>> 
>> typealias AnyObject = class
>> 
>> Is Any necessary?
> 
> Nah, it should be okay to just have “class” there.

This would mean ‘class’ can appear anywhere we expect to parse a type, or would 
we have a special grammar rule for the RHS of a typealias?

Slava

> 
>       - Doug
> 
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