Copying blocks (ie: copying them to instance variables) in Objective-C

Question

I\'m trying to understand blocks. I get how to use them normally, when passed directly to a method. I\'m interested now in taking a block, storing it (say) in an instance va

Answer 1

Copy a block when you want it to stay around. Autorelease or release it when you're through with it. Retain it if you need a long way to spell /* NOP */.

@interface Foo : FooSuper {}
@property(copy) int (^storedBlock)(int);
@end

@implementation Foo
@synthesize storedBlock = mStoredBlock;

- (void)setupStoredBlock {
    self.storedBlock = ^{/*...*/};
    // or: mStoredBlock = [^{/*...*/} copy];
    // but this simple implementation violates the atomicity contract
}

- (void)runStoredBlock {
    int result = self.storedBlock(5);
    NSLog(@"%s: result = %d", __func__, result);
}
@end