Optional properties get unwanted default values in memberwise initializers

[davdroman (David Roman)]

@tera

so it is not treated internally as if was: foo(param: Int? = nil)
but is exactly foo(param: Optional<Int>)

this shows that there are already parts of compiler that treats Int? as Optional<Int> (without = nil). i propose to use the same treatment in memberwise initialisers.

I had this same opinion a year back. Ever since, I've come to understand the issue as @xwu poses it, and arrived to the conclusion that it's better to remove implicit behavior altogether, in order to comply with Swift's core ideal of clarity over brevity. Introducing more rules to the exception is not the way to tackle this issue. We ought to get rid of the exception in the first place.