Silver: catch let as where clause

Elements Silver
1

Swift 3.0 allows the where clause to be used in catch let clause.

do {
         let response = try HTTP("http://wrongdestination.com").performSync()
} catch let error as LakestoneError where error == HTTP.Request.Error.DestinationUnreachable {
         print("Error encountered: \(error.representation)")
}

While catch let error as LakestoneError is valid in silver, adding where to it results in compiler complaining about the syntax.

Do you guys think it makes sense supporting such construct?