# SE-0309: Unlock existential types for all protocols

**URL:** <https://forums.swift.org/t/se-0309-unlock-existential-types-for-all-protocols/47515>\
**Category:** Proposal Reviews\
**Created:** [April 17, 2021, 7:56pm UTC](https://forums.swift.org/t/se-0309-unlock-existential-types-for-all-protocols/47515 "2021-04-17T19:56:29Z")\
**Posts on this page:** 1\
**Showing post:** 195

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**Author:** ![jayton](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/jayton/32/5592_2.png) [@jayton](https://forums.swift.org/u/jayton)\
**Post date:** [May 9, 2021, 9:51am UTC](https://forums.swift.org/t/se-0309-unlock-existential-types-for-all-protocols/47515/195 "2021-05-09T09:51:30Z")

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The “ [Improving the UI of generics](https://forums.swift.org/t/improving-the-ui-of-generics/22814)” design document/submanifesto discusses this kind of constraint, with the syntax `some Collection<.Element == Int>`, but it’s not part of SE-0309 or any other pitch that’s been made so far, so nobody can say “yes, it will be available in \<some version number\>”.

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