SE-0400: State limitations

[AnthonyLatsis]

cc @hborla

See apple/swift#71578.

[AnthonyLatsis]

@hborla ping

[hborla]

I think the original text is correct. Even if you can only define init accessors in the primary declaration of a type, you can add an initializer in another source file that will call the init accessor:

// in FirstFile.swift

struct S {
  var _x: Int

  var x: Int {
    @storageRestrictions(initializes: _x)
    init {
      self._x = newValue
    }
    get { _x }
  }
}

// in SecondFile.swift

extension S {
  init() {
    self.x = 10
  }
}

[AnthonyLatsis]

Thanks. We had a crash report with like the simplest example of an init accessor use across files, and I was not sure if this sentence really meant they could be internal because the forum topics appeared to settle on fileprivate. I could have just inferred it from the inlinable business that follows, really. But I still think this paragraph would benefit from a little more straightforwardness and accuracy (see the latest revision).