From reading around the web and the little documentation available on the entirety of open-source Swift, I've found that functions like print and swap exist either in the standard library, Foundation, or it is built-in to the language.
Would you point me to their documentation and list of other functions that are defined like print and swap?
I would like to know what functions are available out of the box so I don't write my own.
I think this ressource isn't really kept up-to-date any more, but I find it useful for getting an overview of the Standard Library: http://swiftdoc.org/nightly/
Good point, but there's a "but" to this. ;-) The official Apple developer website not only provides the documentation of the standard library but also the language specification of Swift, whereas swiftdoc.org "only" provides the most recent generated documentation of Swift types and functions.