Копирование блоков 2

https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Blocks/Articles/bxUsing.html
Typically, you shouldn’t need to copy (or retain) a block. You only need to make a copy when you expect the block to be used after destruction of the scope within which it was declared. Copying moves a block to the heap.

You can copy and release blocks using C functions:

Block_copy();

Block_release();

To avoid a memory leak, you must always balance a Block_copy() with Block_release().

попробовал так: 

    int j=0;

    __block int i=0;

    typeblock block = ^(void) {

        i+=10+j;

    };

    typeblock block_copy = [block copy];

    typeblock block_copy_2 = (typeblock)CFBridgingRelease(Block_copy(CFBridgingRetain(block)));

    block();

    block_copy();

    block_copy_2();

Возможно что-то неправильно, но главное в том, что получил снова то же значение, то есть

block== block_copy == block_copy_2

https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/WorkingwithBlocks/WorkingwithBlocks.html

The syntax to define a property to keep track of a block is similar to a block variable:

@interface XYZObject : NSObject

@property (copy) void (^blockProperty)(void);

@end

Note: You should specify copy as the property attribute, because a block needs to be copied to keep track of its captured state outside of the original scope. This isn’t something you need to worry about when using Automatic Reference Counting, as it will happen automatically, but it’s best practice for the property attribute to show the resultant behavior. For more information, see Blocks Programming Topics.

A block property is set or invoked like any other block variable:

self.blockProperty = ^{

...

};

self.blockProperty();