在特定代码行上禁用ARC [英] Disable ARC on specific lines of code

问题描述

我把一个项目变成ARC，但有一些代码只能使用ARC禁用。我意识到 -fno-objc-arc 可用于在每个文件的基础上禁用ARC。但是我想知道是否可以在每个函数的基础上禁用ARC。

I am turning a project into ARC, but there are some bits of code that can only work with ARC disabled. I realize that -fno-objc-arc can be used for disabling ARC on a per file basis. However I was wondering if it was possible to disable ARC on a per function basis.

我知道警告可以在每行基础上切换，例如

I know that warnings can be toggled on a per line basis for example

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Weverything"
// Code goes here
#pragma clang diagnostic pop

ARC有类似的东西吗？ （以下是我的假设想法）

Is there something similar for ARC? (Below is my hypothetical idea)

#pragma clang diagnostic push
#pragma clang diagnostic flag "-fno-objc-arc"
// Code goes here
#pragma clang diagnostic pop

推荐答案

这是不可能的。您必须将非ARC代码移动到单独的文件。如果这是Obj-C类中的代码，也许你可以将相关方法移动到一个类别。

This isn't possible. You'll have to move your non-ARC code to a separate file. If this is code in an Obj-C class, perhaps you could move the methods in question to a category.

编辑：

使用Objective-C ++可以解决Obj-C中ARC的一些限制。例如，你可以在结构体中放置Obj-C引用。 （因为他们可以在C ++中有deinitializers）

Using Objective-C++ can get around some of the restrictions of ARC in Obj-C. For example, you can put Obj-C references in structs. (Because they can have deinitializers in C++)

编辑：

这段代码适用于我：

test.h

#import <Foundation/Foundation.h>

struct Struct {
    id ref ;
    NSDate * date ;
};

main.mm

#import "test.h"

int main(int argc, const char * argv[])
{
    @autoreleasepool
    {
        Struct a ;
        a.ref = [ NSObject new ] ;

        Struct * a2 = new Struct() ;
        a2->ref = [ NSObject new ] ;
        free( a2 ) ;
    }

    return 0;
}

这篇关于在特定代码行上禁用ARC的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！