swift - Swift编译器错误: The enum case has a single tuple as an associated value, but there are several patterns here

Question

在Xcode 11.4 beta 3中构建一个项目，我在枚举中遇到了这个Swift Compiler错误:

The enum case has a single tuple as an associated value, but there are several patterns here, implicitly tupling the patterns and trying to match that instead

源代码:

switch result {
case .error(let err):
    //
case .value(let staff, let locations):  // <-- error on this line
    //
}

Result是一个通用枚举，具有 .error和 .value的关联值。在这种情况下，关联的值为tupple。

public enum Result<T> {
    case value(T)
    case error(Error)
}

不要回想起以前曾遇到过此错误，并且搜索该错误不会产生任何结果。有任何想法吗？

Answer 1

我发现您也可以通过将相关值更像元组来处理(通过将其包装在一组额外的方括号中)来消除此错误:

switch result {
case .error(let err):
    //
case .value((let staff, let locations)):  
    //
}