This is all goodness, and eliminates a major source of implicit conversions.
One thing this regresses on though, is that we now reject "x == nil" where
x is an option type and the element of the optional is not Equtatable. If
this is important, there are ways to enable this, but directly testing it as
a logic value is more straight-forward.
This does not include support for pattern matching against nil, that will be
a follow on patch.
Swift SVN r18918
String interpolation invokes convertFromStringInterpolationSegment() function
now. There is no need to add extensions to String to allow custom types to
participate in string interpolation. Just implementing Printable will do the
right thing.
Swift SVN r18104
It is replaced by debugPrint() family of functions, that are called by REPL.
There is a regression in printing types that don't conform to Printable, this
is tracked by rdar://16898708
Swift SVN r18006
