Apple announced on Friday that it is on track to release Swift 3.1 in the spring of 2017. The update will be source compatible with Swift 3.0, and will include some “additive enhancements to the core language,” along with improvements to Linux support and the Swift Package Manager.
Swift 3.1 is intended to be source compatible with Swift 3.0. It will contain a few additive enhancements to the core language as well as improvements to the Swift Package Manager, Swift on Linux, and general quality improvements to the compiler and Standard Library.
Swift 3.1 is intended to be released in the spring of 2017.
It is a strong goal that the vast majority of sources that built with the Swift 3.0 compiler continue to build with the Swift 3.1 compiler. The exception will be bug fixes to the compiler that cause it to reject code that should never have been accepted in the first place. These cases should be relatively rare in practice.
Swift 3.1 will include changes in mainline development only until January 16. After that date there will be a “bake” period in which only select, critical fixes will be made.
Following the middle of January freeze date, Apple will turn its development focus to Swift 4.0.
Swift is Apple’s open source programming language for developing apps for macOS, iOS, watchOS, tvOS, and Linux.