Hi All.
My problems are so weird that I don’t even know what to put in the subject line.
I’m using the latest Swift 3 snapshot, and I’m trying to write a bridge from
[String] to (const char * const *)
Here’s my code:
public struct ArrayBridge<SwiftType,CType> {
let originals :[SwiftType]
let translated :[CType]
//let pointers :[UnsafePointer<CType>?]
init(array :[SwiftType], transform: @noescape (SwiftType) throws -> CType)
throws {
self.originals = array
self.translated = try array.map(transform)
let pointerArray = self.translated.map {
guard let result = UnsafePointer<CType>($0) else {
fatalError()
}
return result
}
}
}
This gives the error:
Expression type '[_]' is ambiguous without more context
or Ambigious reference to member ‘map'
on the line “let pointerArray = self.translated.map {"
Some digging says that this may be helped if I explicitly specify the return
type for the closure:
public struct ArrayBridge<SwiftType,CType> {
let originals :[SwiftType]
let translated :[CType]
//let pointers :[UnsafePointer<CType>?]
init(array :[SwiftType], transform: @noescape (SwiftType) throws -> CType)
throws {
self.originals = array
self.translated = try array.map(transform)
let pointerArray = self.translated.map { item -> UnsafePointer<CType> in
guard let result = UnsafePointer<CType>(item) else {
fatalError()
}
return result
}
}
}
This gives the error:
Cannot invoke initializer for type 'UnsafePointer<CType>' with an argument
list of type '((CType))’
on the line “ guard let result = UnsafePointer<CType>(item) else {“
Can anyone shed some light on this? What is a type with parentheses around it?
I’ve also gotten errors like, “argument (_) -> _ does not match _ -> _”
Thanks!
-Kenny
_______________________________________________
swift-users mailing list
[email protected]
https://lists.swift.org/mailman/listinfo/swift-users
