[swift-evolution] Enhanced existential types proposal discussion
Jan E. Schotsman
jeschot at xs4all.nl
Thu May 26 08:51:22 CDT 2016
On May 26, 2016, at 3:44 PM, Austin Zheng wrote:
> The inimitable Joe Groff provided me with an outline as to how the
> could be improved. I've taken the liberty of rewriting parts of the
> proposal to account for his advice.
Looks like great progress!
A few remarks:
1.I don't see the need for AllOf. A nested existential also acts as a
constraint bundle, so you would have to write
Any<ProtocolA, AllOf< ProtocolB, ProtocolC>>
In a "is subclass of" constraint the superclass also acts as a
constraint bundle, in a sense.
2.If openas never fails why do we need to use optional binding with it?
3. You have a typo in the "where clause" section: where
Collection.Element == Streamable
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