I’d like to pull the implementation of the Objective-C #selector expression into the Swift 2.2 branch:
The actual implementation is in a number of commits that can be cherry-picked:
This proposal contains both a new feature (the #selector expression) and the deprecation of an existing feature (treating a string literal as a Selector). Our intent is to use 2.2 to start migrating existing clients over to the new syntax, which will become far more important with The Grand Renaming in Swift 3.
There is risk here, of course: I changed the way we emit Objective-C selector references a bit, and the Fix-It code for translating uses of string-literals-as-selectors is non-trivial and makes use of another new feature (SE-0021, compound names). That said, I’m not overly concerned about new problems being introduced by this code. I’d love to see better code completion for compound names, but haven’t figured out a good way to do it yet.