There are many place in Swift code where used hard coded values, such as response statuses (200, 201, 404, ...) which can replaced with constants HTTP_OK, HTTP_CREATED, HTTP_NOT_FOUND. Also there is widlly used idiom 200 <= status < 300, that can be replaced as well with something like this is_success(status). I want add modules for defining all required constants (Swift, HTTP). So I think this changes will improve Swift code readability. PS: this is an initial changes in github https://github.com/vitoordaz/swift/commit/7163d5df13ceaf8fc7b53ba812fe16bd7dd31131