快速等效于typedef

Question

在C语言中，我会写类似：

    typedef struct old new;
struct old
{
    int x = 0;
    int y = 0;
};

我无法迅速找到对应的内容。

请帮助我

Answer 1

很快就会像这样：

typealias new = old

struct old {
    let x = 0
    let y = 0
}

Answer 2

“ typealias”是所使用的关键字，它的作用是与typedef类似的迅速。

typealias MLAnimationCompletionBlock = (_ finished: Bool) -> Void

var blockVariable : MLAnimationCompletionBlock = { [weak self] (finished: Bool) -> Void in

       println(" this is a block that has bool input param and with void return")

    }