Objc中2维指针作为输出参数时由ARC及@autoreleasepool引发的血案

#import <UIKit/UIKit.h>

#import "AppDelegate.h"

@interface Something : NSObject

- (void)doWithError:(NSError **)outError;

@end

@implementation Something

- (void)doWithError:(NSError **)outError
{
@autoreleasepool
{
*outError = [NSError errorWithDomain:@"Emergency" code:999 userInfo:nil];
}
}

@end

int main(int argc, const char *argv[])
{
@autoreleasepool
{
NSError *error = nil;

　　　　　// Sometimes EXC_BAD_ACCESS when return from this method.
[[[Something alloc] init] doWithError:&error];

// At this point, the main thread gives EXC_BAD_ACCESS.
NSLog(@"%@", error);
}
return 0;
}

@interface Something : NSObject

- (void)doWithError:(NSError **)outError;

@end

@implementation Something

- (void)doWithError:(NSError **)outError
{
NSError *error = nil;
@autoreleasepool
{
error = [NSError errorWithDomain:@"Emergency" code:999 userInfo:nil];
// Do something
}
if(error)
{
*outError = error;
}
}

@end

int main(int argc, char * argv[])
{
@autoreleasepool
{
NSError *__autoreleasing error = nil;

[[[Something alloc] init] doWithError:&error];

// At this point, the main thread gives EXC_BAD_ACCESS.
NSLog(@"%@", error);

int a = 1;
++a;
}
return 0;
}