Preparation for Swift 6

[kkebo]

Currently, warnings are shown when compiling swift-image. It means that swift-image cannot be compiled in Swift 6. Moreover, it seems that Swift 6 will be released in the not-too-distant future.

$ swift build
Building for debugging...
...
/path/to/swift-image/Sources/SwiftImage/AnyImage.swift:63:31: warning: generic parameter 'Pixel' shadows generic parameter from outer scope with the same name; this is an error in Swift 6
    private class AnyImageBox<Pixel> {
                              ^
/path/to/swift-image/Sources/SwiftImage/AnyImage.swift:3:24: note: 'Pixel' previously declared here
public struct AnyImage<Pixel> : ImageProtocol {
                       ^
...

(Xcode 15.2, Swift 5.9.2, macOS 14.3.1 arm64)

[koher]

Sorry for the delayed response. I have released a new version where the image types and pixel types conform to Sendable. While it does not yet support building in Swift 6 language mode, it can still be built in Swift 5 language mode using the Swift 6 compiler. Therefore, it should work fine when used with the Swift 6 compiler.