swift234

Sema:  ObjC type parameters can capture generic types

For example in:

public final class MyCache<V> {
  private let cache: NSCache<NSObject, CacheValue<V>>

  public init(cacheName: String) {
    self.cache = {
      let cache = NSCache<NSObject, CacheValue<V>>()
      return cache
    }()
  }
}

The metatype that we pass to the NSCache initializer captures the generic type
'V'. Therefore, the closure needs to be a generic function type.

SR-1951
rdar://27410181