# 自动闭包

**自动闭包**是一种自动创建的闭包，用于包装传递给函数作为参数的表达式。

这种闭包**不接受任何参数**，当它被调用的时候，会返回被包装在其中的表达式的值。

在声明时，需要`@autoclosure`指定自动闭包

```swift
// customersInLine is ["Ewa", "Barry", "Daniella"]
func serve(customer customerProvider: @autoclosure () -> String) {
    print("Now serving \(customerProvider())!")
}
serve(customer: customersInLine.remove(at: 0))
```

> 过度使用 autoclosures 会让你的代码变得难以理解


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