如何使用ARC处理'require(...，bail)'语句? [英] How do you handle 'require( ..., bail)' statements with ARC?

问题描述

我正在查看 Apple的示例代码中的Square Cam .我想在使用ARC的现代项目中复制其某些功能.但是，有大量的require语句，例如:

I'm looking through some of the sample code for the Square Cam in Apple's sample code. I want to replicate some of it's functionality in a modern project using ARC. However, there are a ton of require statements such as:

BOOL success = (destination != NULL);
require(success, bail);

哪个会生成编译器错误:

Which generates the compiler error:

进入受保护范围.

Goto into protected scope.

我的问题是-在使用ARC的项目中处理此类语句的适当方法是什么?

My question is -- what is the appropriate way to handle such statements in a project using ARC?

推荐答案

我遇到了相同的问题(具有相同的示例代码).代码如下:

I had the same problem (with the same sample code). The code looked like this:

BOOL success = (destination != NULL);
require(success, bail);

//Initialise some variables

bail:
//Deal with errors

我在声明的块周围添加了括号，以使它们的范围清晰明了:

I added braces around the block with the declarations to make their scope clear:

BOOL success = (destination != NULL);
require(success, bail);
{
    // *** Initialise some variables ***
}
bail:
{
    //Deal with errors
}

它为我解决了问题.通过查看此内容，我还了解到您有时可以扩展构建错误以获取更多详细信息.

And it solved the problem for me. Through looking at this I also learned you can sometimes expand build errors to get more detail.

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