[swift-evolution] Public struct init is unexpectedly internal

Charlie Monroe charlie at charliemonroe.net
Mon Jan 30 03:26:43 CST 2017

Unfortunately, I've come across this several times, but read here that it's intended behavior. If I remember correctly, it has something to do with the automatically generated initializers - it's implicitly internal so that you don't expose the initializer by mistake.

The most annoying about it is, however, when the constructor has several parameters - when you declare 

	public var text: String

Swift automatically generates an initializor that takes a text parameter, but it is internal. When you have 4-5 members, the initializer gets quite long.

And if you want to have it public, you need to declare it and then assign each member, which is tedious. I'd prefer some kind of an annotation on the struct, for example:

public struct SomeType { ... }

> On Jan 30, 2017, at 10:12 AM, David Sweeris via swift-evolution <swift-evolution at swift.org> wrote:
> So I’ve got this code in a package called “SomeLib":
> public struct SomeType {
>     public var text = "SomeText"
> }
> and then, in another package, write this:
> import SomeLib
> print(SomeType().text)
> and then run swift build, I get this error:
> error: 'SomeType' initializer is inaccessible due to 'internal' protection level
> "Well that’s odd… there isn’t even an initializer to be internal or public”, I said to myself. Then I proceeded to futz around with it for a while before having a lightbulb moment:
> public struct SomeType {
>     public var text = "SomeText"
>     public init() {} //this fixes it
> }
> In cases like this where the struct is public and all its stored properties are both public and already have values, should we make the implicit init() function also be public? Seems like the “least surprising” thing to do.
> - Dave Sweeris
> _______________________________________________
> swift-evolution mailing list
> swift-evolution at swift.org
> https://lists.swift.org/mailman/listinfo/swift-evolution

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