Swift build time optimizations
1 , Nil Coalescing Operator
2 ,ArrayOfStuff + [Stuff]
3, Ternary operator
4, Casting CGFloat to CGFloat
5, Round()
https://github.com/RobertGummesson/BuildTimeAnalyzer-for-Xcode
https://medium.com/@RobertGummesson/regarding-swift-build-time-optimizations-fc92cdd91e31?
http://hyyy.me/2016/12/01/SwfitCompileTimeSpeedingUp/