Using @lazy properties in functions causes build errors

Question

I am trying to limit a classes scope to within a function. This seems to work:

func foo() {
    class MyClass {
        var s = ""
    }
}

I can create instances of MyClass within the foo() function.

However, when I attempt to add the @lazy specifier to a property...

func foo() {
    class MyClass {
        @lazy var s = ""
    }
}

... I get the following build errors:

• Global is external, but doesn't have external or weak linkage!
• invalid linkage type for function declaration
• LLVM ERROR: Broken module found, compilation aborted!

---

Note: If I move the class out of the function's scope, the code compiles:

class MyClass {
    @lazy var s = ""
}

Why is this failing, and how should this error be resolved? If it cannot be resolved, is there another way to use @lazy properties inside of functions?

Answer 1

The following code works for me:

func foo() -> String {
    class bar {
        lazy var baz = "qux"
    }
    return bar().baz
}

foo() // prints "qux"

Looks like there was a bug in the early Swift laguage version, which has been reolved.

Answer 2

I can confirm akashivskyy's observation. I've tried it as well and the this code works for me as well:

func foo() {
    class MyClass {
        var variable = "string"
    }
    let instance = MyClass()
    println(instance.variable)
}

foo() // "string" is printed

It's not the first time for me that I've actually encountered some issues in earlier Swift versions. I mean it's still a pretty young language and thus it needs always some improvements and bug fixes.

Are you using the newest version of Swift and Xcode?