swift - 对于 Swift 中的结构，如何默认公开成员初始化器？

Question

我有一个定义结构的 Swift 框架:

public struct CollectionTO {
    var index: Order
    var title: String
    var description: String
}

但是，我似乎无法使用另一个导入该库的项目中的隐式成员初始化程序。错误是:

'CollectionTO' cannot be initialised because it has no accessible initialisers

即默认的合成成员初始化器不是public。

var collection1 = CollectionTO(index: 1, title: "New Releases", description: "All the new releases")

我必须像这样添加自己的初始化方法:

public struct CollectionTO {
    var index: Order
    var title: String
    var description: String

    public init(index: Order, title: String, description: String) {
        self.index = index;
        self.title = title;
        self.description = description;
    }
}

...但是有没有办法在不显式定义 public init 的情况下做到这一点？

Answer 1

引用手册:

"Default Memberwise Initializers for Structure Types The default memberwise initializer for a structure type is considered private if any of the structure’s stored properties are private. Otherwise, the initializer has an access level of internal.

As with the default initializer above, if you want a public structure type to be initializable with a memberwise initializer when used in another module, you must provide a public memberwise initializer yourself as part of the type’s definition."

摘自 "The Swift Programming Language" , 第 "Access Control" .