# \[Pitch #3\] SE-0293: Extend Property Wrappers to Function and Closure Parameters

**URL:** <https://forums.swift.org/t/pitch-3-se-0293-extend-property-wrappers-to-function-and-closure-parameters/43857>\
**Category:** Pitches\
**Tags:** propertywrapper\
**Created:** [January 15, 2021, 4:51am UTC](https://forums.swift.org/t/pitch-3-se-0293-extend-property-wrappers-to-function-and-closure-parameters/43857 "2021-01-15T04:51:44Z")\
**Posts on this page:** 1\
**Showing post:** 63

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**Author:** ![hborla](https://sea2.discourse-cdn.com/swift/user_avatar/forums.swift.org/hborla/32/27563_2.png) [@hborla](https://forums.swift.org/u/hborla)\
**Post date:** [January 27, 2021, 4:16pm UTC](https://forums.swift.org/t/pitch-3-se-0293-extend-property-wrappers-to-function-and-closure-parameters/43857/63 "2021-01-27T16:16:23Z")

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> [@xAlien95](#):
>
> @hborla, is this intended? I thought the goal was to hide the backing storage's type unless the property wrapper creator doesn't explicitly make it public/accessible through the projected value.

If the associated value type is the backing wrapper type, it's already exposed. I only changed it from Filip's take because this is what was suggested in the [decision notes](https://forums.swift.org/t/returned-for-revision-se-0293-extend-property-wrappers-to-function-and-closure-parameters/42953) from the first review:

> 1. The functionality that allows "unwrapping" property wrappers in the pattern of a closure argument (e.g. `{ (@Binding item) in` ) could alternatively be imagined as an orthogonal feature that applies to all patterns. If it were, such an unwrapping could work consistently in other places where patterns exist, for example `for @Binding item in items` , in `switch` case patterns, `if case` , etc. It would be interesting to explore such a direction.

The suggestion was for pattern matching to "unwrap", not create a new property wrapper.

Honestly, I was hesitant to include an example at all, because this direction obviously involves design work and the example raises a lot of questions. Remember that this is just a future direction and the feature is orthogonal to this proposal.

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