ARC, self and blocks

Question

I thought I understood the usage of self in a block that is copied is a no no.

But in an attempt to clean my code i enabled a bunch of warnings in Xcod

Answer 1

Strong reference to a weak reference retains an object. It could be important in following case

__weak typeof(self) weakself = self;
[aClass doSomethingInABlock:^{

     [weakself allocateSomething]; // (1)
     // ..... code (2)
     [weakself freeSomething];  // (3)
}];

If Weak receiver will be unpredictably set to nil in line (2) resources could be successfully allocated in (1) but not freed in (3). To avoid such problems strong reference could be used.

[aClass doSomethingInABlock:^{
     typeof(self) selfref = weakself; 
     [selfref allocateSomething]; // (1)
     // ..... code (2)
     [selfref freeSomething]; // (3)
}];

Now if selfref is not nil in (1) it will also be valid in (2) and (3).