[Proposal] Add syntactic sugar keyword in for conditions checking collections

[dwing73]

Having just performed a Javascript code review where there was a conditional statement with the syntax of if ("some-value" in this.SomeValuesList) for checking if this.SomeValuesList contains "some-value", I really liked the syntax and I would like to propose the similar syntactic-sugar syntax for C#.

It would basically be a more succinct of writing if (this.SomeValuesList.Contains("some-value"))

[ufcpp]

#8720

[dwing73]

@ufcpp - yes, without the set keyword, that would work in my book.

[huoyaoyuan]

#4255 #5708 #8146

[dwing73]

Ahh thanks. Nice to know it is a popular idea!

[dwing73]

#8146 looks the best proposal. Upvoted it.

[CyrusNajmabadi]

Closing as dupe.