问题
Swift 3.0 is coming up with Xcode 8, what is the minimum iOS / OS X system version required to use Swift 3.0? Is that swift 3.0 support iOS 7 ?
回答1:
Minimum OS X to run Xcode 8 which is compatible with Swift 3 is OS X 10.11.4 (OS X EL Capitan)
And I think Swift 3 does not support iOS 7
As you have minimum target in Xcode 8 is iOS 8.0
And as per App Store support measurement iOS 8 (11%) and iOS 9 (84%) better that you stop support for iOS 7 as per my opinion. iOS 10 is coming soon.
来源：https://stackoverflow.com/questions/38092144/swift-3-0-or-swift-2-3-minimum-system-version-requirement-and-is-it-deployed-in