> On Mar 16, 2016, at 5:27 PM, Alex Martini via swift-evolution 
> <swift-evolution@swift.org> wrote:
> 
> To help keep proposals moving forward, the Swift core team has set aside some 
> time specifically for design discussions of upcoming proposals.  Below are 
> some rough notes from the yesterday's discussion.
> 
> These are informal comments, intended to guide the proposals in directions 
> that draw constructive feedback. You are welcome to ignore the feedback, 
> agree with it, or disagree with it.  As always, the formal decision doesn't 
> happen until after the review period ends.
> 
> SE-0048 
> <file:///Users/alexmartini/DevPubs%20Git%20Repositories/Swift%20Language%20Review/_build/html/LR_MeetingNotes/MeetingNotes-03-15-2016.html#se-0048>
> This is straightforward and 95% implemented. The contentious point is that it 
> starts simple: you can’t add constraints to the type alias.
> 
> We want to avoid type-based metaprogramming.
> 
> Unclear if this would work:
> 
> typealias StringDictionary<T> = Dictionary<String, T>
> It need to infer that T must be hashable. Maybe it’s only 85% implemented.
> 
> 

Clarification here: the example is

typealias DictionaryToStrings<T> = Dictionary<T, String>

Either we infer T to require Hashable, or we call this ill-formed and require 
the user to write

typealias DictionaryToStrings<T: Hashable> = Dictionary<T, String>



        - Doug

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