Swift: 为什么 init?(length length: Int) NSMutableData 的初始化程序会失败？

Question

内存分配可能会失败，但我认为 Swift 无法处理这种情况。 github 上的代码调用了一个不可失败的初始化器

public convenience init?(length: Int) {
    let memory = malloc(length)
    self.init(bytes: memory, length: length, copy: false) { buffer, amount in
        free(buffer)
    }
}

编辑：代码来自 Swift 3.

中的 native-Swift Foundation 框架

Answer 1

来自 swift- 用户列表：

"Swift’s policy on memory allocation failure is that fixed-size object allocation is considered to be a runtime failure if it cannot be handled. OTOH, APIs that can take a variable and arbitrarily large amount to allocate should be failable. NSData falls into the later category."-克里斯

Swift: 为什么 init?(length length: Int) NSMutableData 的初始化程序会失败？

Swift: Why is the init?(length length: Int) NSMutableData's initializer failable?

initializer

nsdata

swift

swift2

failable