Do not discard casting information

[charlieMonroe]

Currently, casting information is discarded:

[item setIndex:(int)index];

Becomes simply item.index = index. With Swift really forcing type-safe environment, where are no implicit conversions even between Int and UInt, this is a place I need to go back to and add the casting manually.

Proposal:

• if you are casting to a primitive value (integers, floats, boolean), do the following: ObjC: [item setIndex:(int)index]; --> Swift: item.index = Int32(index) (int is a 32-bit integer).
• if you are casting to an enum, do the following: ObjC: value = (MyEnum)index; --> Swift: value = MyEnum(rawValue: index) - since casting directly to an enum isn't possible in Swift.
• if you are casting to a class type (or id) use as?: ObjC: myVar = (NSTableView *)[self superview]; --> Swift: myVar = self.superview as? NSTableView. In case of id, use AnyObject. Standard class conversions apply - NSString -> String, NSArray -> [AnyObject], NSDictionary -> [NSObject : AnyObject].
• if you are casting to anything else:
  • if it's a pointer (e.g. void *, or float *, or mystruct *), use the following: ObjC: floatArray = (float *)malloc(16) --> floatArray = UnsafePointer<Float>(malloc(16)) - (UnsafePointer<Void>, UnsafePointer<mystruct>, ...)
  • at this point, I can't think of another valid cast, in which case I'd throw an error.

[drkameleon]

Not sure about how... complete my implementation is (we'll see, I guess), but as of the upcoming 2.3 I'm marking this as "fixed".

For now:

• Type cast are now taken into account (while they were being ignored)
• Primitive values are being casted using the proposed way (+ the usual type conversions)
• Other types are casted by as? which seems like a rather universal (and safe) way

Looking forward to input once 2.3 goes out (I'm doing my best to release it today).