The old ones were:
- print/println
- printAny
- printf
- Console
The new printing story is just print/println. Every object can be printed.
You can customize the way it is printed by adopting Printable protocol. Full
details in comments inside stdlib/core/OutputStream.swift.
Printing is not completely finished yet. We still have ReplPrintable, which
should be removed, string interpolation still uses String constructors, and
printing objects that don't conform to Printable will result in printing
mangled names.
Swift SVN r18001
difference is that a concrete type's conformance to an existential
type is considered a conversion (but not a subtyping). Relationships
between two existential types are (non-trivial) subtyping relationships.
Swift SVN r2718