I use the dot property conversion, not the overloading in general use. I also have such reservations about using overloading for casting in production. What I do use, is the series of extensions for single letter dot property conversions, the extensions without the protocol extending, that I also used in Swift 1.2. Sorry if that was unclear...

1.5 has an exact representation in floating-point, so adding 1.5 + 1.5 is always going to give you 3.0 in floating-point, also exactly represented.

Then whatever the type of integer rounding you do, you will get a solid 3.

If you need to convert float to int, use an explicit rounding mode. Then adding 0.1f (or rather the closest fp approximation) ten times will round up to 10.

I've read that as do 1.4 + 1.4 give you 2 or 3 - if you cast 1.4 to int first, you'll get 1 + 1 = 2, but otherwise 1.4+1.4 = 2.8 -> to int = 3