Is it possible to use Xcode 6.3 but stay with Swift 1.0?
Using the iOS 8.2 SDK does not help, and I could not find any switch for the Swift version ...
EDIT: I have an extension build in Swift 1.0 which I do not want to touch, but update my main project
If you're having syntax problem then you can convert it to latest syntax. Also there is no way of using 1.0 in xcode 6.3
No, that is not possible. Xcode 6.3 comes with Swift 1.2. If you are concerned about compatibility, you can convert your swift 1.0 code into Swift 1.2 using Xcode 6.3Edit->Convert->To latest Swift syntax
来源：https://stackoverflow.com/questions/29555083/is-xcode-6-3-with-swift-1-0-possible