如何声明在Swift 2中计算的属性“throws”？

问题描述

class SomeClass {
  var someProperty: Int {
    throw Err("SNAFU")
  }
}

对于像上述代码，swift二进制抱怨错误不处理，因为封闭函数未声明为throws。

For code like the above, the swift binary complains 'error is not handled because the enclosing function is not declared 'throws'.

如何在上面声明'someProperty''throws'？

How do I declare that 'someProperty' 'throws' in the above?

class SomeClass {
  var someProperty throws: Int {
  }
}

和

class SomeClass {
  var someProperty: throws Int {
  }
}

和

class SomeClass {
  var someProperty: Int throws {
  }
}

似乎没有工作。

推荐答案

截至Swift 3：

您不能从计算属性中抛出。如果你想要抛出，你必须使用一个函数。 部分的声明部分Swift编程语言仅将 throws （和 rethrows ）列为函数和初始化程序声明的关键字。

You cannot throw from a computed property. You must use a function if you want to throw. The Declarations section of the Language Reference part at the end of The Swift Programming Language only lists throws (and rethrows) as a keyword for function and initializer declarations.

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